Bruh. The next sentence literally acknowledges that this is a possibility. Why do so many people stop reading once they think they find a sentence they can use to say, "wElL aCsHuAlLy..."?
Yes, many people support causes that, in some way or another, work against their interests. Some black people voted for Trump, as did many poor people. Some women support abortion bans. Life is complicated and it's very rare that an issue is so siloed off that you can agree with every part of it. Find me any universally (or even broadly) supported idea, even just amongst very poor people, that doesn't support capitalist ideologies.
Defund/Abolish The Police, for example, was largely seen as a "black" cause. It's on BLMs list of "demands." This despite the fact that most black people, especially black people living in high crime neighbourhoods, wanted the same or greater police presence.