For what it's worth, I think GILBERT Timmy is debating the points far more eloquently than I'm able to, but I've dived in already so I might as well continue

I disagree with trying to split this into two distinct categories. The social aspect and the business model are orthogonal, and there's nothing inherently wrong with either. The problem is when you tone down elements that are fun, replace them with elements that are compulsive, and then essentially put paywalls between the player and their next reward.
I think this is the crux of the anti-Farmville sentiment. The problem with this argument is that "fun" is incredibly subjective. The thought process behind the anti-Farmville camp seems to go something like this:
I don't find the game fun. Therefore it isn't fun. Therefore no-one can find the game fun. So what's keeping the millions of players playing it? ZOMG MIND CONTROL!
It's nonsense. The players clearly
do enjoy playing these games, otherwise they wouldn't play. They certainly wouldn't pay. They experience a sense of progress, a feeling of creativity - they enjoy it. The games are perhaps too simplistic for the tastes of you and I, but that doesn't mean they're devoid of fun. If they were devoid of fun, people wouldn't play them.
Characterising the microtransactions in those games as paywalls is pretty unfair and fallacious as well. Admittedly I haven't played Farmville, so I could be wrong about that game, but of all the social games I've seen (including other -Ville games), there's little (perhaps no) content that can't be attained by not paying a penny and just being more patient. The vast majority of players of freemium games never pay a penny to play - they just log in when it's convenient, do what they do, log out again, and eventually get the stuff they want. The people that pay are just the ones who want a way to shorcut the process. I don't see how there's anything wrong in that. It's not a paywall, it's a completely optional shortcut.
The "energy" (or whatever other depletable, slowly-recharging resource a game might use) generally serves to actually limit the length of any given session playing one of these games. Hard-wired into their design is a mechanic that ensures they'll be played in short bursts, in a schedule that suits the lifestyles of the players. How many "proper" games have that? Hell, Blizzard might have stopped some of their more obsessive players from fucking
dying if they had the same mechanic.
The problem is that Farmville provides mechanisms to encourage you to harass your friends in order to make your own gains in the game.
And that's why I wanted to make a distinction between the "social" aspects of these games and the monetary aspects. I find the friend-spamming uncomfortable too, and there's a lot of room for improvement there. That said, again, it's unfair to characterise the spamming as only being beneficial to you. If you spam someone who is already playing the game, and they respond by clicking on the button to magically gift you the Strawberries Of Power (or whatever the hell it is you need to progress), they get ingame bonuses too. The benefit is mutual, and it doesn't cost anyone anything. Spamming people who aren't already playing the game? Yeah, that's pretty crappy.
Does Farmville tell you up front which features require real world money? Does it mention that certain things are only possible if you recruit friends? Does it tell you that you will be essentially taunted by being shown things that other players had to pay money to achieve?
No, Farmville doesn't tell you that stuff in advance, and it should. But again, I don't know of anything which you MUST pay for to attain, and even if you do, I think you must be an incredibly sensitive soul if you feel "taunted" by seeing someone owning a piece of virtual property that you don't. I don't hear of anyone being upset that other people's XBox avatars have clothing or accessories that they don't. I happen to have a set of that overpriced Horse Armour in Oblivion - who would be upset if I posted a screenshot?
There is also a strong thread among gamers which states that you shouldn't be able to introduce external resources to improve your standing within the game, as a point of fairness.
Sure, I understand that point of view. But nobody is making the gamers that hold that opinion play these games. Nobody is making
anybody play these games.
Different types of players that allow some players to get privileges and benefits over the others is something else. Imagine how chess tournaments would be if you were allowed to pay to have pawns upgraded to bishops.
As GILBERT Timmy pointed out, none of these games (at least none I know of, and certainly not Farmville) are competitive. They're co-operative. If your chessboard is full of bishops, that's fine with me - I'm not playing against you. If you can lend me a copy of one of your bishops for a bit, and in return I'll clone a couple of my pawns for you in case you need them, everyone wins.