Interesting take, but the majority of those movements tend to be 'White' collegiate suburbanites.
Not that its restricted to them, but many minorities, particularly more recent arrivals, are very much Capitalists. 70% of new small businesses in America are started by immigrants, and many who are illegals tend to partake in grey economies for obvious reasons. Things may change with some of their children, not wanting to slave for little to show but sweat, but they too are more inclined towards traditional modes of finding success.
Leaning Left doesn't automatically mean Socialism, Communism, or Anarchism, even in the beginning of the 20th Century when such movements were taking hold and more vigorously. Capitalism itself was originally radically Left. Left Leaning folks tend to be more open to new ideas or willingness to crack a seemingly exclusive system they were never quite a part of, except as the exploited and deprived as you pointed out.