1) I have had the protection racket play on me too many times by other programs if I didn't pay up. MS is not going to do this, Whats the point? it's free.
2) When was the last time you used it? They have been right on the nose with current malware and spyware issues. Maybe they have improved as of late?
If I disappear from a discussion please forgive me. My 24-7 business requires me to split mid-sentence to serve them. I am not ducking out, I will be back later to catch up.