Which is why I own guns. Capitalism is the only economic system consistent with liberty and individual rights.
All else is theft. And thieves are to be shot.
Well...actually....we can say to heck with them. We (and, in fact, just about every society I'm aware of) does precisely this. Oh, the rich may be called the nomenklatura in the USSR, or the nobility in some other society, but fundamentally the poor are out of sight and out of mind.
As to your second point, no - neither we nor anyone else says find another country. (Though Mexico comes close to doing this as they export poor people!). What we can do (and have done) is to supply psycological opiates. Television comes to mind. The lottery, with its many promises of rapid, unearned riches, is another.
And the thing is, that there are people who exit the lower strata and become successful to some degree. As long as they perceive some chance of doing so, they'll submit to the system.
On your last point - the need to deal with the issue - I'm not so sure. People want equality when they're below the mean, and they detest it when they're above it. And as long as the "dream" of moving from poor to rich survives, people will perceive themselves as being able to advance. Hence, they won't oppose the existing order of things very strongly. All IMHO, of course....