It's not just Trek; much of the 60's & 70's TV can bee seen as a series of morality plays: Trek, Bonanza, every cop show of the era, even up to Buck Rogers and (original) Battlestar Galactica.
The 80's, 90's and 2000's have been marked by a consistent move away from morality plays. (Going into all of the reasons why violates board rules. It's not just the end of the TV censors.)
The 1920's to 1940's saw a similar trend in literature, followed by a societal backlash against such in the late 40's and the 50's, and then a counter-revolution in the 60's and early 70's.
It's cyclical. I'll be happy when the current trend towards shades of gray and moral relativism fades. I miss my morality plays.
[RANT MODE ON]
Just to make myself feel better, and hammer home a point, because I think your's is worth reiterating, we're seeing stuff on television today that would NEVER have been considered for production, much less a concept, being aired and posted on Youtube. I'm not talking about so-called "adult" entertainment, but stuff that's pure ⌧ographic-sensationalism minus the sex. Heck, if it had sex in it that might make it interesting.
The net, ideally, as envisioned by those designing it in the 20s and 30s, was meant to be a commercial endeavor to be sure, but also meant to be a conduit of information. Which it is. Regrettably those who have the most free time, punks, now dictate that which gets translated into entertainment.
Think about all the raunchy jokes and ideas you and your friends had when you were school boys. That sensibility used to be truncated about mid high-school, because you were expected to grow up. Now it's considered to be mainstream and "cool" to have degraded tastes and moral relativism.
Call me a prude, old fashioned, an idiot, moron, "paranoid", whatever, but I quit reading mainstream books and watching mainstream TV in the early 90s because of the shift in market focus. Blue humor's always been around, even on broadcast, but even the blue-humor of pre 90s television was in far better taste than today's. Not to sound too glib, but the adult humor was, well, more adult.
Today the entire focus of the internet, to me at least, seems to be what we in middle school called a giant "slam book". Broadcast news is sensationalized, online news, to me at least, reads very simply and doesn't give any kind of in depth analysis. That, and the headline news is usually tabloid news.
Again, the sense of right and wrong is completely lost. I don't think society is going to crumble. Au contraire, it'll flourish as always, but will be all but unbearable for those of us with a sense of purpose.
So it is that I end this rant.
*steps off soapbox, calls for the crier to summon Doctor Franklin from Liberty Hall*.
[RANT MODE OFF]
p.s. truth of the matter is that mainstream entertainment is now on a pay-per-view basis, so us poor folks get stuck with ghetto-television.