Social media companies and "the left" are not the same. Although they surely have some overlap (just as social media companies and "the right" surely have some overlap), conflating them entirely with each other is simply false. We cannot assign political conspiracies to entire industries.
I don't think the claim is that social media is inherently leftist, but rather than leftists have mounted attacks on all social media companies that don't actively censor right-wing opinions (see current ad boycott targeted at Facebook). I think the success of these campaigns are extremely concerning and a reminder that peace and prosperity are not a given.
Companies should be accountable to their customers. When a large group of those customers collectively exercise their rights to let a company know the company's values don't align with those customers, that seems like a pretty reasonable demonstration of the market.
