Because ultimately voting with your dollar doesn't matter. It's ineffective and it does nothing. It's a myth that if people don't like [x], then they won't buy

Because ultimately voting with your dollar doesn't matter. It's ineffective and it does nothing. It's a myth that if people don't like [x], then they won't buy from companies that support/enact [x] -- the market can take care of collective action problems! It ends up being a convenient way to push the responsibility onto some amorphous other person and say "not my job". People don't like sweatshops. They don't like abusive monopolies who engage in shady anticompetitive practices like Uber. And yet most products are made in sweatshops, and Uber is wildly successful. I'm not sure why people (myself included) don't do this. I suspect a lot of it is information/guilt overload; our global capitalist system is so dysfunctional that almost any purchase you make is contributing to something morally abhorrent. So in order to get by and have a daily life we just have to turn that part of our moral compass off when we make purchases to some extent. In the end, it will never be effective to allow the market to decide matters like this: if a bar of soap whose purchase guarantees the murder of a baby for $2 is sitting next to a normal one on a supermarket shelf for $4, people will fight tooth and nail for the chance to kill that baby. Because they figure if they don't, somebody else will, and why waste $2? That's assuming they are even informed -- businesses, when necessary, will spend millions of dollars on PR and advertising campaigns to ensure their customers are uninformed and that the market is dysfunctional. The only solution is regulatory power, to through taxes or some other means delete the businesses with immoral practices from the market.