I have a son that just turned 17. At 16 he was VASTLY more mature and rational than he was at 10.... the difference was not merely one of degree, but an entire paradigm shift in the quantity and quality of his ability to understand the realities of life, apply reason to problems, and project the future consequences of his actions. Indeed, I could safely say he is almost a different person, fundamentally, than he was at age 10.
Still didn't want him having sex at 16, of course.... but making it a crime for someone older to have consensual sex with him at 16 still seems a bit harsh to me even though it is my own kid we're talking about here. I'd be pissed off, sure... but applying the SAME criminal penalties to that as to raping a 10yo? Hell no! If someone had sexually abused him at age 10 I'd kill them. If, OTOH, some 25yo girl slept with him and it was HIS idea that would piss me off but it isn't the same thing as raping a 10yo!
As for putting a 16yo in adult prison or executing them, under certain special circumstances I could accept that. A 16yo should have enough sense not to murder or rape people; if they don't there has either been a serious flaw in their upbringing or they went WAY wrong and aren't fit to be loose in society for sure.
Sure, some 16yo's are blithering idiots... but they shouldn't be. Mine wasn't. Probably because I expected and insisted on better out of him.