But, on the other hand, growing up doesn't necessarily have to mean "for adults" either. Shows like Gargoyles & Digimon Tamers were way ahead of their times- even considering the maturity of adult shows of the time(s) as well-
See, this is what I meant when I said maturity is subjective.
I've never seen Digimon Tamers, but I watched season one of Gargoyles just recently and I honestly don't see much about it that elevates it above most kids shows, and the deeper elements I do see are basically cribbed from X-Men, which had been airing for years before Gargoyles came along. Moreover I still found plenty cringeworthy (like that one of their recurring villains--the Steel Clan--are a bunch of television actors whose suits happen to be fully functional. Plus we still had cringeworthy dialogue--like that time they make star wars references when they're trying to control a jet that's about to crash and kill them).
Then again though, with most television then and now I find nobody acts like a real person and there's always going to be plot points, characterizations, and premises that make no sense, or make sense only if you assume the characters are horrible people.
That's the other problem with shows "growing up." The fact is there's very few adults in society who are actually of any sort of maturity level so they really wouldn't know how to write something "mature." Just look at how some people get onto Lord of the Rings (the book) for being slow, not having enough action or T&A and actually requiring you to read words more than three syllables long, but then turn around and praise something like Dragonlance which gives them a party of characters who are awesome and can kick all sorts of ass and where the women pretty much all exist to be objectified by the males and all problems can be solved by violence, but its respectable because they sometimes play lip-service to the other side. Maturity!
That's the great thing about children's shows. They're at least honest in their childishness. And when they're not childish, you get to praise them for their stunning maturity despite expectations. With shows aimed at adults, its impossible to ever see anything but problems.