I can’t understand why the kanji and radical 光 are called sunlight for a primary meaning as opposed to just light. 光 as vocabulary has the primary meaning light and jmdict doesn’t even list sunlight as an alternative meaning. 日光 is sunlight and I can’t find vocabulary in WK with the primary meaning to do with sunlight that doesn’t have 日. So it’s not like the 光 kanji alone is indicating sunlight in other vocabulary.
So why is the primary meaning of 光 radical sunlight? It’s confusing. Maybe I’m a little sore because I just mistook the vocabulary reading of 日光 for 光, but I still think the radical 光 should be light, not sunlight, unless I’m missing something.
Could be just in order to make the meaning a bit more narrow given that in English “light” can also mean “not heavy” and also “a source of illumination”, both of which are not really appropriate for 光. Contrast with 軽 and 灯 for instance.
“Radiation of light” would be more accurate for 光 but that’s maybe a bit complicated for a radical.
Perhaps. You could still have sunlight as a secondary meaning, and the piceratops mnemonic already makes it clear it doesn’t mean lightweight. The vocabulary in the same level also cements meaning. So why not just swap the primary and secondary meanings of the kanji for simplicity and clarity?
Calling it radiance or whatever might be going over the top as the vocabulary in the same level is just light. Although it might be a better secondary meaning than sunlight. The radical doesn’t come for another 40 levels and is one of those copied from the kanji. You’d have long since learned the meaning by the time you encountered it.
I agree completely with that, in fact from very early on I decided to never fail radical reviews (using undo scripts) because I found that delaying kanji unlock just because you missed a rather arbitrary radical meaning wasn’t worth it overall.
As you say, you have a lot of opportunities to review and consolidate that later anyway, in more meaningful context.