And that proves...what? That every single human in the 23rd century is like Kirk, and that every single human in the 24th century is like Picard or Janeway?The fact of the matter is that the humans on Star Trek are, by and large, very different from us. Would you say Kirk is greedy? Picard? Janeway, then? They certainly don't seem greedy from my perspective.

They're lead characters, heroes of the show. Of course they're going to be better, braver, more ethical, more honorable than your average person.
And no, it's not a fact of the matter that they're "very different from us". If they were very different from us, it would be incredibly difficult, if not impossible, for the audience to relate to them. But it is not.
If you mean to say that "we" are greedy, that's not true either, there is no "we". People are different. Some are very greedy, some are less so, some are not at all. Some are brave and some are not, some are honest and some are not, etc. It only stands to reason that humans of the 24th century are different as well. <sarcasm>Unless Federation has some creepy technique how to lobotomize people in order for them all to conform to the concept of the ideal human.</sarcasm>
The premise is, IMO, that the human society has evolved. Which is possible, and which has actually happened to the human society in real life.Do I believe humanity capable of such a transition? Not really. But the premise of the show is that humanity has evolved, that the people of the 24th century are different from us, and it's explicitly stated on many occasions that they've overcome greed, and I assume the explicit mentions of the fact that there is no money in the 24th century are intended to bolster this fact.
Not that the human race has literally evolved. Trek writers might have shown themselves to be clueless about how evolution works in quite a few episodes, but they would have to be idiots to believe that there can be a significant evolutionary change in any species over a period as short as 400 years.

I beg to differ. It is far, far more implausible than transporters, warp drives, replicators... Heck, it's even less plausible than time travel and alternate universes. We're witnessing the huge technological advancements that happened over periods of just a few decades, and many of the technologies we have today would have looked impossible and almost 'magical' a century ago. But to change the psychological makeup of the entire human race in just a few centuries? Has the human race changed that much in the last several millennia? The societies have changed, the culture and the beliefs and the way of life has changed, but the basic human emotions and motivations?It may seem implausible to you, but it's actually less implausible than transporters and warp drive, so you shouldn't have much trouble suspending your disbelief.
