This is absolutely not true. The publishers get very little of a say on what Steam does, as evidenced by the fact that a bunch of them, including Activision and EA, arguably the two most powerful third party publishers, left in a huff over fees and microtransaction revenue splits... and then came back because Steam is the only game in town.

So no, Steam isn't the good guy having their arm twisted by evil publishers, they are a large corporation that invented most of the practices in both digital distribution and games as a service, including this one.