The difference between F2P and P2P is based soley upon what the company thinks they'll earn the most money from. I've seen F2P games that destroy P2P games. I've seen even more F2P games that are on par with P2P games. The way the company wants to gather money doesn't play that critical of a role in determining the actual quality of the game. My number one example would be Cabal. It's a brilliant, brilliant MMO that's completely free and, in my opinion, tops WoW and Aion (based on videos and screenshots).
It's possible to say that making a "bad" game P2P is stupid, but consider this. For a P2P game, every player that plays is required to pay. For an F2P game, not everyone in the game pays to play, nor do many of the players pay a fixed per-month standard of money towards cash shop. So even if you have only 50k people playing a P2P game for $15 a month, it's not that far off from a population of 100k people playing an F2P game and about 75% of the population pooling in about $10 a month for cash shop. All in all it usually balances out, but in my opinion, F2P is always the stronger option.