I'd still pick Xavier for the same reason I believe in progressive taxation and centre-left politics: My happening to be born with more wealth, power, or inherent ability is pretty much the lottery of birth.
I'm American, which means I'm not guaranteed anything close to the same comforts that, say, a Frenchman is*, but that's just coincidence.
Does Solid Snake think he deserves a higher place in society because he's a great soldier? No, he understands that not everyone can, or should, be a good soldier, and that a good deal of his ability comes from being a clone of the greatest soldier ever, Big Boss, who himself learned most of his stuff from The Boss.
Much of our place in the world is inherited: race, sexuality, wealth, physical features, diseases, eye color, etc. The rest is decided almost purely by chance. The fact that I'm here
posting in this forum right now instead of posting in a LiveJournal is again, chance. The fact that I deeply love a medium that most no one else understands is chance. I'm not going to blame people, I blame the lottery itself, and, at the same time, I know my Serenity prayer.**
Thus, if I were born with incredible powers, I would use them for "good", that is, I would use them to fight for what I thought was right, or, lacking powers that help me only in combat, would use other powers to directly help people. Not because it's necessarilly what I want, no, what I would want, probably, would be some permutation on revenge, but out of duty to decency.
*Actually, I'm the son of a 25-year Air Force veteran, so I do get a pretty sweet health deal. It really does cover everything. Demand the public option from your congressperson now!
**Just for note: New Atheist.