No it would not be. Nobody is barring non-white people from Bitcoin. There is no oppression. There is no far-right neo-nazi agenda. It's just a matter of culture. African-Americans predominantly don't have an interest in open-source P2P currency projects. Society is not going to crumble into a Caucasian-driven tyranny because of this. Cultures may change, adapt, stagnate and so forth but nobody is going to be "oppressed" because of predominate interests among them.
Historically for much of the time voting was not restricted to whites or males, just to landowners. It just so happened that almost all the landowners were white males.
A Bitcoin economy would be the same: The people with power would be the early adopters (that's us! woo!), who are overwhelmingly white and male.
Well, it also ended up landowners had the most at stake when it came to democratic decisions while non-land owners had nothing of relevance. Civil rights and such were a societal force of the day and legislation did not touch said issues.
Anyways, I don't believe in an amount of wealth judging how much a person has. It's the means that facilitate that is the real issue. Bitcoin can only be a liberating cause in that sense since there is no central issuing authority.
I think that's what the OP is getting to.
(Not saying that's what you said - just pointing out that this type of thought (as you pointed out) disproportionately negatively affects blacks over whites)