...expect them to, at all. I do expect them to be exposed to life and learn from it and grow from it. I am not a 'learn it from a book' person when it comes to things like this; driving, drinking, etc.
You're argument is that a 21 year old is more mature and going to make better decisions than an 18 year old. Well, I can't argue with that, but that is an apples and oranges comparison.
Try these;
Who is more responsible at 21, a kid who has been drinking, or legal to do so, since they were 18, or a 21 year old who has never had a sip? I'll take A.
Who is a better driver, an 18 year old who has been driving for two years or an 18 year old who just got their permit? I'll take A.
Now, I do applaud you that you are consistent and would rather raise the voting age and the military age rather than lowering the drinking age.
I, for damn sure, don't think anyone under 30 should have the right to vote, so, I'd actually go for that, 21 to vote.