My issue with P2P continues to be the issue that caused me to leave WoW after nearly 3 years of playing. It's not pay to play; it's pay to enter. If you want to revisit a game just to look at the character(s) you've fondly spent x amount of time raising up. Not even to take 5 steps. Just to reach the character screen, select one character, and enter the world. BAM! 15 bucks. No options for a lesser installment like 1 dollar for one day or 3 for 5. The whole month or gtfo. Coincidentally, the first game that ever implemented something even remotely similar to a more flexible payment plan was a F2P game I continue to play to this day. It was such a novel idea I actually remember calling the purchasable service in question reverse subscription. And the features that were paid for? Nice perks, but nothing you absolutely needed in order to play or even to have a good time.
I don't want to be tied down to one game due to a subscription, because then I feel obligated to get my money's worth from it. It's bad enough in the MMO world that taking a break from a game makes you feel like everyone else has passed you by, but to make you feel like you just blew 15 dollars for nothing is where I draw the line. This gets even worse if there are other subscription games you want to play alongside it.
Every additional subscription makes the value of each preceding subscription that much worse. The model only works if you want to play one game and only one game, and as such undermines the effectiveness of the entire subscription-based model when people naturally gravitate to one subscription-based game just because paying for several subscription-based games while only receiving a fraction of the benefits isn't nearly as feasible or desirable. It's so bad that people aren't even willing to TRY another subscription based game even if the game turned out to be really good, which is why so many up-and-comers either die out or are forced to go F2P. Subscription-based games don't encourage healthy competition; they encourage one, extremely healthy monopoly. I guess a euphemism with a positive spin on that is "quality over quantity."
On communities, let me just say that yes, there are less douchebags in P2P. There are also less nice people in P2P. But not proportionately. In any MMO I've played, I've found that the strongest communities are the self-policing ones, and some of the best communities I've belonged to are in the F2P domain. The only thing worse than a douchebag is a douchebag with money, and since we're speaking in sweeping generalizations here, P2P games are breeding grounds for douchebags with disposable income.
Have you ever seen a douchebag with an overly strong sense of entitlement because they dropped a little money down? Try working retail some time. They congregate at the register on a daily basis.
On bots and hackers, many F2P games are really good at dealing with both. Yes, many subscription games tend to have the edge here, but competent GMs and a self-policing community working together can achieve comparable results.
Lastly, microtransactions are not the devil. When handled stupidly, they can be a blight on a game, and I've seen my fair share of blatant cash grabs disguised as "games." But when handled properly, they can be as consumer-friendly as the subscription-based model. People like to point out that many F2P games in effect cost more per year to play than P2P games, and my rebuttal would then be, "What's your point?" If we're speaking only in terms of money, you might have one, but if we're speaking in terms of getting your money's worth, that point becomes lost. A player might be willing to pay more of their own volition in a game if they feel like they have more control over where their money goes. I'd argue that paying 50 bucks for the shiny thing I want and intend to use to its fullest completely beats paying 15 dollars just for the right not to get stopped at the login screen when I enter my username and password correctly. Being willing to pay more in a F2P game also undermines the "If you're not willing to pay a subscription, you're not as big a fan as me" argument many of the more insufferable P2Pers like to throw around.
Some years I pay more in F2P than I would have in a P2P. Some years I pay significantly less. Either way, I was content with every purchase because I found the value of my purchase to be 100% satisfactory.