Why can’t wanikani recognize what I’ve done and suggest that I didn’t really mean to enter the on’yomi and instead do the wiggle and suggest that I enter the meaning?
Yes, I know about the ignore script, and that’s one of the only places I’ll use it, but it would be nice if this could be an option natively.
They are unlikely to change their position on how to handle incorrect answers (even if we all can understand why you answered incorrectly in that particular example).
It’s not impossible, but many users have requested they handle typos or these kinds of errors differently for a long time, and they have kept things the way they are that whole time, despite many other changes.
I’d say this is closer to how they ignore/shake a blank submission or when there’s English in the reading input. Granted, handling this requested case sounds harder, but it seems the same in principal.
Yeah, if I enter the kun’yomi on the kanji page they’ll wiggle, but if I enter the on’yomi on the meaning page I get the big red bar of disappointment. I’d argue that the latter is the more benign mistake of the two.
Oh yeah, I do that all the time also. 
But that’s not the same thing. That’s telling you that the reading is a correct reading, just not what you were taught and what they expected you to answer. Secondly, kanji don’t always ask for on’yomi.
The kanji pages always expect on’yomi. Vocabulary is different and I expect to get the answer wrong in that case.
Not true at all. Just as an example from level 1, かわ (the reading taught for the kanji 川) is not on’yomi. There are plenty of other examples.
Edit to add:
In addition to 川 all of the following by the end of level 3 teach kun’yomi in the kanji lesson:
丸, 夕, 手, 犬, 玉, 田, 目, 矢, 父, 母, 戸, 引, 広, 冬.
If you enter another reading from the one taught in the lesson, that’s still a correct answer, so that’s why it wiggles.
Well I guess shows you what I know. … next to nothing …
Honestly, this is something you’ll naturally stop doing over time, because you get subconsciously used to the different appearances for different prompts (black or white header for the question, prompt says “Answer” in English or “答え” in Japanese).
I know this for a fact because when I switched to a different color scheme using [Userstyle] WaniKani Breeze Dark, I suddenly found myself making this kind of mistake a lot. I had several hundred reviews per day back then though, and noticed that I stopped making those mistakes after just a couple days.
I agree with your suggestion wholeheartedly, especially since WaniKani has a pretty garish UI where colors can mean multiple things (item type and SRS level) and the meaning vs reading prompts do not stand out as visually unique in the way that, say, the kanji vs. vocab (pink vs purple) do. This, to me, is a design problem that sometimes makes me overlook whether I’m being asked the meaning or the reading. My brain responds way more to color prompts than text prompts, so the item type catches my attention while the meaning/reading text gets skimmed over by my brain as secondary information.
When you’re drilling reviews over and over repetitively, accidentally entering a reading rather than a meaning is what I call “an honest mistake”, not an incorrect answer. It’s not really something you can control 100% of the time, and I think just getting the big red “wrong” and unnecessarily delaying that review further is more punishing of your day’s stress level, busyness, alertness, focus, brain type, and a number of other factors, rather than your knowledge of the topic, since you entered a correct answer for that item (assuming you did write the correct reading), just not the one it was asking for.
That said I don’t expect them to change it. I use the ignore script for this reason. Just wanted to say that I agree with you.
Edit after reading Kai_973’s comment… holy crap I never even noticed the difference in black vs white background when asked for a reading vs meaning, and I’m on level 7… Thanks for the heads up. I think it will help me.
Thanks for the tip. I never even noticed the black vs white color change and I’m on level 7. I think that will help my brain out a lot.
But honestly, how is the system supposed to know that? It’s not a mind reader. So the only thing it can do is assume it’s an incorrect answer. Also, this issue isn’t so simple as there are a number of Japanese loanwords that have made their way into the English language.
The system doesn’t know that. The creators should though, and should program it to just “jiggle” and ask for the meaning again when you accidentally enter the reading, just like they did with the on’yomi vs kun’yomi issue. That’s what the OP said and I don’t know why that isn’t clear.
I can see no harm from a learning perspective as you’re not going to find any examples where typing the Japanese reading of a word is going to accidentally get you a “correct” answer on an English meaning of that word. If there are any occurrences like that at all, I’d be surprised, but I’m sure they are very few if so.
It could happen on 缶 (onyomi is かん, meaning is can).
“can” is both the meaning and an accepted way to type the kana かん.
Off the top of my head.
It’s not that it’s not clear, I don’t think. It’s just that if you put the reading into the meaning field (and it doesn’t coincidentally match like above, or is a loanword like below) it’s just a wrong answer. There’s really no way to say it’s actually a right answer. Which is very different from the on/kun thing.
I guess the other possibility is that someone thinks the word is like “tsunami,” a loanword from Japanese. Especially if they are not a native English speaker, they might remember the Japanese reading better than the English meaning. If they think “hmm, was it a loanword in English maybe?” and try the reading, but it’s actually not, and then it wiggles… they were wrong but they won’t be marked wrong.
Sure, an obscure example, but WK has just decided to not handle things that way and avoid anything like that.
What! You’re level 7 and you didn’t notice? I am finding that hard to believe.
Wouldn’t you notice since the on’yomi wouldn’t be converted to hiragana? Or are you using your own IME to convert to hiragana instead of letting WK do the conversion?
Personally I’d have a hard time making this mistake, since if I typed in “shou” and it didn’t convert to “しょう” I’d know right away that I was being asked the meaning instead of the reading.
Or to give the classic advice, if you find yourself running into this issue a lot, try slowing down during reviews slightly.
I’m on level 7 and I didn’t notice either 
I’m level 56 and never consciously thought about this 
But I practically never have the problem OP is describing so my brain at least noticed it by itself.