WordPress was doing a good job for me by offering a platform for blogging. Things were fine and i was not really concerned about security as my blog traffic wasnt high.
The actual reasons are
1. My ISP in India blocks wordpress. I dont know whats the ISP real intention.
2. Signin using username is encouraged in wordpress which made my login once in a month or two very troublesome. I resetted password many times.
3. wordpress adds gravitar or avator as identity for author but blogger gives link to google +.