They have a left wing biased, but it gets blown way out of proportion. ESPN's biggest problem is exactly what this article is talking about. They have spent so much money on TV rights, that it causes price of getting cable to go up and more people are cutting the cord because of that (not because they are liberal)
I think writers often have a bit of a left-wing bias, but many of the talking heads lean more right-wing. Consider all of the withering criticism you would see on these sports shows for Colin Kaepernick or Chris Kluwe. It's probably a money thing, in many respects: writers aren't wealthy, the talking heads usually are.
In the US the sports media often talks about topics that are only tangentially related to sports. Like whether or not a sports team should accept an offer to visit the white house (a tradition for teams that win their league). Or about players that refuse to stand for the national anthem.
I agree that their problem is completely rooted in the fact that they have overpaid for sports contracts, coupled with the fact that they have no option but to continue to overbid for future contracts.