the reason i choose f2p over p2p is the same as a number of people have said.
i live a very busy life. i have school and work etc and if i play a p2p game there may be days even a week go buy in a month were i don't have time to touch it. and then i'd feel guilty about not playing and then obligated to play. with f2p i don't get that feeling. plus i don't usually buy cash up except on special occasion and so in the end i'm not in the situation as a person spending more on f2p than p2p
anyway lately because of time constraints and the "keep up with the joneses" mentality involved in mmo gaming i have come to focus on console gaming again.
yes i'm a sexy free and single ಠ_ಠ