The difference is whether you're in the majority/socially-recognized ruling majority or not. I think it's shortsighted to think that all blacks are alike and that they can be targeted with some uniform channel programming.
Even so, I think it's even more ludicrous to think that such a wide swath of the concept of "white people" makes any demographic sense to begin with. The diversity of social background, classes, and experiences of people under the "white" umbrella is too wide to make any cohesive, unilateral presumptions, IMO.
For example, you take the son of Italian immigrants and the daughter of Irish immigrants and say that they have that much in common because of just their lighter skin color? Really?
The whole concept of "white" people is a false construction, IMO, as it really means anybody who isn't black, who isn't Asian, who isn't too light of a Latino, etc. And any collective people defined more by who they aren't than by who they are is a joke.
Which, IMO, is why the concept of a "White Entertainment Television" channel would be considered oddly racist. I wouldn't see it as racist so much because I don't see "white" as really being a race, per se. But to the degree that society defines whites by what they are not rather than what they cohesively are, then by definition it's about exclusion rather than inclusion. And exclusion television doesn't exactly come off as socially acceptable.