I agree, Kirk basically talks about how he overcame his hatred for Khan which made him able to listen to him and even temporarily work together with him to achieve a common goal. But one should be wary about generalizing personal experiences, Kirk's friend has to do the very opposite and unleash his anger to stop Khan.
Sure, speeches can work for you or they cannot. But unlike Kirk's speech Picard's speech does not merely match his own motivations but those of most people or at least those of most Starfleet folks. I don't recall Kirk, Riker, O'Brien, Tuvok or Reed being out there because of the large paycheck. Picard's words in FC might sound pretentious to many folks but there are correct. Political or ideological issues make these folks unable to realize something purely technical, that pecuniary incentives do not matter in a world in which a machine can create virtually all consumer goods and that some folks wanna not just eat crisps and play holonovels all day long. Gee, if I do this for more than a day I am becoming depressive! I do at least need the illusion that I do something useful with some of my spare time.
This is not a new idea, Keynes wrote about it in Economic Possibilities for our Grandchildren a century ago:
Thus for the first time since his creation man will be faced with his real, his permanent problem-how to use his freedom from pressing economic cares, how to occupy the leisure, which science and compound interest will have won for him, to live wisely and agreeably and well.
and Aristotle wrote about it in Nicomachean Ethics more than 23 centuries ago:
The happy life is thought to be one of excellence; now an excellent life requires exertion, and does not consist in amusement.
So it looks like the hyper-hedonistic notion that people never exert themselves unless they gain means for consumption for their efforts is not "natural" but contingent.
About Marcus, how can starting a war without the consent of the parliament or even the executive not be wrong, how can wanting to kill the crew of an entire Starfleet vessel in order to protect his Augment secret not be treason?
The former beats what the conspirators tried to achieve in TUC (they wanted to prolong the Cold War, not put the Quadrant on fire) and the latter beats what Luther Sloan did or planned to do. Moles in high position, genocide, Sloan was no angel and I would have been the first one who wanted to see this guy tried and shot (or put into a dilithium mine for the rest of his life). But you gotta give the devil his due, unlike Marcus he hasn't killed his own folks.
If Marcus' actions aren't evil we really are in a postmodern nightmare of total relativism.