I think it’s the other way around. WK likes to teach simpler kanji first, whatever JLPT level. Trying to teach 電 on level 3 would scare most people.
The first few levels keep it simple, it takes the easiest kanji from JLPT and elementary school. So I agree, they also took this into consideration. But simplicity is not everything, some kanji like 旦且召尺矛寸 are in the end despite being simple and arguably very important in phonetic compounds.
In the charts (wkstats) you can see that the JLPT and Jouyou parts are filling quickly; I think people would rightfully complain if they have to wait to level 60 to finish all N5 kanji for example 
Yeah, it seems like after a certain level they just don’t weight simplicity in anymore and go by JLPT… you’ve got a point. They process of increasing complexity seems to be for the first few levels.
In that case I would appreciate seeing your kana site/app. I’m not 100% with all my kana, the diphthongs in particular.
The worst radical is “shruiken.” It’s literally only used in one kanji, and it’s only one stroke away from that kanji 互.
Don’t forget raptor cage, which is also used only in one kanji (久).
But at least that makes it even less relevant to remember the radical’s name.
I’m pretty sure 六 was introduced as a radical, but never used in any kanji at all. It’s not on the list of radicals now, so either they removed it or I dreamed the whole incident.
Speaking of one stroke away, 易 is introduced as the radical “gravity”, but only actually appears exactly like that in the kanji of 易しい - every other time WaniKani invokes it, it’s got an extra horizontal stroke, as in 湯.
They removed it 
I remember being near the level where you learn it and then it suddenly didn’t exist anymore.
Honestly, my biggest radicals issue might be that they don’t do this enough. A number of mnemonics end up being a laundry list of “so you’ve got a spoon, a car, a mouth, on the ground next to a grave…” or whatever and that’s just too eclectic an assortment of things to form a good mental picture.
But if there’s a single radical that uses multiple of those building blocks and makes up part of the new kanji, that can be a lot easier to remember. It might reduce a 4-5 part kanji to 2 parts, which often allows a better mnemonic story to be told. You can only tell so many stories about an assortment of random crap lying on the ground before they start to lose their potency.
Those more complex “radicals” also often make up the phonetic component of a lot of kanji. Those give you great hints as to the reading, so the more they can be emphasized, the better.
The problem isn’t that kanji are being used as radicals. That’s great, as you said. The problem is that WaniKani wastes your time making you “learn” this kanji as a radical instead of just using the kanji directly. It’s extra time and effort for no reason. I believe this is what the OP was getting at as well.
You can add mnemonics during lessons though, right…?
At least, if what you’re doing is adding a note on it.
The thing you can’t do by default is add synonyms during lessons, but there’s a script for that.
@seanblue, Yes, I think that’s the (first) point being made by OP. I find it frustrating too. If I have already learnt that 食 means “eat”, why I am I iterating through the usual 4 hour, 8 hour, 1 day, 2 day review intervals just because 食 now has a blue background?
That is totally what I meant. Thanks.
Unfortunately scripts are a bit troublesome because I access WK from a bunch of different machines, including my mobile phone.
The poop one still confuses me lol. I always get it wrong, doesn’t look like poop xD
Rather.
It looks like a short version of 糸, which means thread. And perhaps not entirely surprisingly, it’s called “short thread” in Japanese.
And aside from all that, the mnemonics which use that radical always make me feel like I need to take a shower after reading them.
I believe it is all about drip feeding you vocab. Usually when you learn the Kanji before the radical they only give you some vocab that relates only to that Kanji. However Radicals=/=Kanji, and that is seen with Kanji like 曲 (music). You learn 曲 as a Kanji first before you learn the radical, because you won’t learn any other Kanji that uses 曲 as a radical, like 農, until later levels. So they just give you the 曲 as a Kanji first in order to drip feed you just the Vocab that relates to the music Kanji, then in later levels they can give you more vocab that uses 曲 as a radical by introducing it as a radical thus unlocking multiple Kanji that use 曲 as part of their building blocks, and thus unlocking tons more Vocab.
It is just controlling the amount of vocab given to you at any given time. Introducing 曲 as a radical too early would open up the floodgates on a lot of words you are not planned to learn yet.
Which is precisely why I added “short thread” as a synonym at the earliest opportunity. 
Oh god, this. I remember when I first saw the lesson for the kanji 葬. It’s got five radicals: flower, ground, spoon, bad, and twenty. I think my eyes bugged out for a sec. Then I looked at the kanji for a second and saw 死 hanging out in the middle and relaxed and made up my own mnemonic. It’s much easier making a mnemonic about death and twenty flowers than whatever mess of a story five radicals gives you.
I like the concept of radicals and mnemonics fine, but this one really dropped the ball.
I generally like the WK mnemonics and often find them useful. But I will also love to see Kanjis or part of Kanjis used as building blocks for later Kanjis. There are quite a few examples where this would be helpful. I don’t even think one needs to turn Kanjis into radicals for that - just mentioning the Kanji in the mnemonic may be helpful.
For example, consider the 屋 Kanji (roof, shop). It consists of quite a few radicals and it makes it hard for me to remember the mnemonics. But I noticed that this Kanji is pretty similar to the 室 Kanji (room) that I already learned. So “room with a flag on top of it” mnemonics made me remember this instantly. Note that the 室 is a bit different from what is used in 屋 so making 室 a radical may lead to some confusion. But updating the mnemonics to include this kind of connections between Kanjis would definitely make remembering some Kanjis so much easier for me.
I currently use notes to write down such mnemonics. I am not sure if there is an easy way to share notes, but it may be that creating these kind of mnemonics may be possible within a community, without even asking WK staff to do it.
It’s the infamous boob grave 至!