Sure I can. And I do. Developers are making these choices, after all. I understand the economic drive behind them, but that doesn't get the devs off the hook.
My point is that some users want Facebook or Google login and get mad if you don't have it. Other users don't want them and get mad if you do. Because you have to decide whether to include the SDK when you build the app, it's impossible to make both groups happy at the same time.