Star Dreck was shit from the start, and Rottenberry's "vision" was at best naive claptrap and at worst unredeemable drivel.
That was kind of the point of Star Trek, or at least the point of TNG and to a lesser extent TOS. I'm sorry that you didn't get that, it wasn't for everyone, but it was and is the reason why the reboot completely sucks ass and has nothing in common with Star Trek other than the title and character names.
Is the near-utopia presented in The Next Generation attainable? Probably not, human nature being what it is, though if anything made it possible it would be an abundance economy with virtually limitless supplies of energy that can literally make food and consumer goods out of thin air. The notion of people working towards the common good rather than personal enrichment is a lofty one, hence the fiction part of Science-Fiction.
It was a lot more enjoyable than the dark depressing crap that passes for entertainment these days, like Law and Order Rape (err, I'm sorry, Special Victims Unit) or even some of the darker Sci-Fi stuff, like the really misanthropic episodes of Babylon 5 or Battlestar Galactica. Yeah, I get it, character conflict is fun to write. Does anybody know how to write uplifting stories anymore? It'd be nice to have something more grown up than Frozen to turn to when I need to escape for two hours.
Bad "science" (only loserboy nerds known as "trekkie pedophile geeks" can delude themselves into believing any of that shitty technobabble can ever be related to real science)
Star Trek at its best was never about the "science". It was about the story and the characters. As long as they remained consistent about the fake science who cares? Go watch the third, fourth, and fifth seasons of TNG or any of DS9 or TOS. The technobabble was there, but it played by a known and consistent set of rules. The particle of the week deus ex machina technobabble crap was primarily a 7th season TNG problem (the writers clearly ran out of ideas) and long running Voyager phenomenon.
B5 was vastly superior to DS9 (which was a shameless ripoff)
The only parts of B5 that DS9 ripped off were the Messiah Complex/Emissary crap of the Commanding Officer. Coincidentally, that was also the least watchable part of DS9. I wanted to shove Sisko out an airlock when he stopped talking about "wormhole aliens" and started talking about "Prophets".