At what price? A slight inconvenience of signing in when I want to use their service, doesn't seem too bad to me.
It's fine if you don't care about your data privacy, some people do, I'm just explaining why because you asked. I'm definitely not screwing myself here, I still get what I want, and they get less out of me for it. However, your data DOES do something for them, that's why they give you services for "free". You are the product, you're fine with that, I'm not here to tell you you're wrong for being fine with it, just as I'm not wrong for not being fine with it. Most people are fine with it.