I assume your circle is mostly tech people? Outside that bubble, it's pretty obvious. People just want easy, don't understand security in many cases, it's the simplest path.
Even absent the above. Imagine a signup flow. I can either click <Sign Up With Google> or I can go through a manual flow with input fields. The former is much faster than the latter. It surprises you people choose the path of least resistance?
Even absent the above. Imagine a signup flow. I can either click <Sign Up With Google> or I can go through a manual flow with input fields. The former is much faster than the latter. It surprises you people choose the path of least resistance?