Any moderate opinion risks getting misrepresented by those who have extreme views on the same issue. That is why some people believe I am a proponent of the Free2Play and micropayment business model, when in fact I'm broadly neutral on it, and have repeatedly stated that are both good and bad microtransactions, and that I don't play Free Realms any more because I found their microtransaction system to be bad for gameplay. But as I also pointed out that there is a general trend towards this business model, and some people hate that trend with all their heart, I tend to get a lot of angry comments when writing anything not completely condemning microtransactions.
Having said that, I do agree with Ancient Gaming Noob Wilhelm2451 that there is a risk with Free2Play games in that they can be changed by a patch from a good microtransaction system to a bad one. I only played very little of Battlefield Heroes, the game Wilhelm2451 is talking about, so I can't talk from own experience. But the Ars Technica article he cites sounds pretty dire. What is clear in any case is that if you were previously playing without paying any money to EA, you will in future be a lot less competitive if you continue playing on the same schedule. You'd either need to grind a lot more to earn victory points, or start paying money to stay at the same level of performance. It is easy to see how that would make players upset.
Something similar happened to Free Realms as well. SOE found that apparently too many players were happily playing that game without paying, by sticking to the Free2Play classes and not using the premium classes. So they patched the game and now you can play any class for free, but only until level 5, and you need to pay if you want to play any class beyond that level. I'd say its a case of turning an already bad micropayment system into a worse one, but the principle of a patch changing the business deal remains the same.
In more general terms, the issue is that this are basically stealth price increases. Assuming that at least some players will want to keep up with the Joneses without increasing the grind, EA will make more money out of Battlefield Heroes in the future, which is obviously the idea behind the patch. More players are likely to pay SOE for keeping their characters beyond level 5. So even if a game has a balanced and good system of micropayments, a patch can at any time turn this into a bad system, by simply changing some parameters on how hard it is to achieve something in game which otherwise has to be bought, or by changing the pricing model. It would be a lot harder to do such a stealth price hike for a subscription based game. Monthly subscriptions could be raised, but that is a pretty obvious change, and not a stealth hike. The only way a game company could deliver less value for money in a subscription based game would be to slow down or stop the addition of content by patches.
By the way, this is a perfect opportunity to tell you the latest joke about EA and their Battlefield series of games: EA originally wanted to call their latest release in this series Battlefield: Electronic Arts. But then somebody in marketing told them that this was too obvious a self-promotion, and so they called it Battlefield: Bad Company instead. :)