What is more likely is that more of the minors who are charged as adults are minorities, which is already known to result in disproportionately longer sentences.
Why in your theory doesn't that happen for 1st and 2nd degree felonies?
The racism in the system applies across all levels -- for adults and kids, for 1st and 2nd and 3rd degree felonies. It could be that this particular effect is a result of some kind of unequal application, sure. But I wouldn't automatically assume that racism applies very specifically to 3rd degree felonies committed by juveniles in a way it doesn't for 2nd degree felonies, or for 3rd degree felonies committed by adults, or what have you.
It sort of sounds like you're assuming that something you already know (that the system is racist) is definitely responsible for anything and everything about the system, and anyone who doesn't see it that way automatically must just not know the system is racist, and you need to explain that to them. Yes, I know the system is racist.
So as long as we are both speculating, mine is based on actual disproportionate outcomes in criminal sentencing and yours is based on an assumption that the disparity had a logical explanation.
It seems like you're just not grasping the mathematical concept I'm trying to explain (or maybe, just not even understanding that there might be anything to grasp other than that the system is racist.) And then saying the only explanation for anything in the criminal justice system is always racism. IDK man. I tried twice to explain it, and it seems like it failed both times.
If you want to understand, let me know, and I'll try again. If you just want to tell me that the system is racist (which, again, it is) and the problem is just that I'm too stupid to know that it is racist and need you to explain it to me, I think I'll go off and do something else instead.