The counter argument is that standardized open protocols are important. So if a big corporation moves to adopt a standardized open protocol, it's a good thing for everyone, even if said corporation is sketchy, evil, or whatever.

It's kind of like Microsoft's adoption of XML for Office save files. Yes, they had ulterior motives, and the result isn't completely satisfactory for third parties who want to parse the save data. But it's still miles better than the previous situation where things were completely closed off.