Because the free market is bullshit. It always results in a few major companies hand-shaking and fucking over consumers. Smaller businesses almost never have a chance and are just as easily bought out. To win in this capitalist iteration of society, you have to be the worst and greediest you can be. Add in the fact most people prefer to remain ignorant or are just generally apathetic from years of conditioning, and ‘voting with your wallet’ rarely really works. You should still do it though of course.