I can see your point, but institutional racism can be combated by changing individual attitudes, as well. I just had to take issue with wildcat's implication that minorities cannot be racists, which is completely false.Well, that's the thing about hegemony; it exists in the fiber of the environment. It is expressed in tiny details... like what is taught in schools and what is left out, how language patterns are judged as correct/proper or incorrect/improper, how schools receive some funds through property taxes, etc.
It exists because of historical assumptions about what is valuable and not valuable, and it's so woven in that it's sometimes kind of invisible. There are the people who work against it, the people who default to it, and the people who actively deny that there is a problem.
An example of the hegemony in action: History Education. For a long time, what American children learned in school was white American history. Beyond a mention of slavery, African American history was simply not covered. This is a problem for lots of reasons (it presents to children an imbalanced and dishonest-by-omission history, it affects the self-concept of kids, especially African American ones, etc). Somewhere along the line, someone called bullshit on this practice and started to change this. One way they tried to raise awareness of this deficit in education was by implementing "Black History Month."
So those are the folks working against it. The people who default to it don't really think about it or consider the problem of not teaching this history. They just shrug and do their homework. And every once in awhile, there will be a denier--frequently a member of the "ruling class" (ie, very likely a white male individual) who complains about Black History Month (or Women's History Month, or whatever) because they see it as "reverse discrimination." These are the people who see the system as totally fine the way it is and who regard these efforts as unnecessary and even offensive.
I do think that things are changing (because of the efforts of people working against the system). The system IS better than it was, and more African American history is taught than before outside of BHM. More African American authors are a part of the American Lit curriculum. But if everybody just complied with the system, we'd still be learning only the history and literature of white male Americans and drinking from separate water fountains.
The system is less racist than it was, sure. That's because there have been individuals working against it for over a century now.
I don't mean to excuse individual racists; they're definitely a problem. But what still exists in the system is still more harmful to the group than what individuals can inflict. Individuals act upon individuals; the system acts upon the whole.
EDIT: Also, individual racism, while awful, is more VISIBLE than that which is ingrained in institutions. You can vanquish an enemy that you can see much more easily than one that is camouflaged.