The Thin Line Between Love and Hate
I think you're (deliberately?) missing the point of SoF and Solomon's. You identify the trouble that Jagex is having with subscribership, and with online ad revenue down everywhere it's increasingly difficult to monetize free players on that method alone. This is a common trend among MMOs: at some point they peak in members, and after that reduced revenue makes it difficult to afford to produce new content, which means losing members, etc. The most effective solution so far is to move from a subscription model to microtransaction based one. When Lord of the Rings online did this, it literally saved the game.
At this point, we're one update away from a completely f2p game. Imagine a consumable item that gave you 1.33x XP for a month, for $10. Enough members would probably buy one (if they didn't also have to pay for membership) to maintain their current revenue, and I'll bet a lot of free players would buy one occasionally (when they have the money, or in a month when they're going to be playing a lot), generating more revenue. Right now, the barrier to membership is that it's not worth buying just one month; at the end of the month you get to keep any extra xp, but all your new items become useless. With this system, occasional purchases become useful, especially if they're flexible. Only play on weekends? Instead of buying the month, spend the $10 on a 10 pack of 2x XP for 1 day. Or, dare I say it, 1 item that gives you 10x xp for 1 day.
Yes, it's conceivable that they could get enough revenue from just the cosmetic items. Team Fortress 2 does just that. TF2 doesn't have the same kind of experience system, though, and I think it's unlikely that Jagex would ignore what would be a popular product. And yes, there will be a lot of complaints. It's likely that they will lose some current members, who feel like their accomplishments are now meaningless. That's true of every update that makes xp easier, though (Runespan, anyone?), and the new active players should more than make up for it. If, in the end, it keeps the game viable for years to come? That seems like a worthwhile trade.
Now, I say this as someone who is f2p, and who would benefit most from this change. But this would probably get me to throw a few bucks their way every so often, and I imagine I'm not alone. Since f2p is the majority of players, that's hard to ignore.
It is undoubtedly true that Jagex can make more money with selling xp boosts and the like. The two basic questions are how much the integrity of the game is important to those in charge and how seriously the danger of too many players leaving is taken. You say LOTRO was saved by these microtransactions (I have no experience with this, will just take your word), yet Maplestory went down the drain. I'm not quite sure where Runescape has to be put on that scale. Until now, players have been pretty lenient with the new features, but the general feeling is quite negative, and you have to keep in mind that the SoF, RaF etc. are not the type of microtransactions for widespread use.
As Alg pointed out, Jagex really aren't good at PR, and if they turn to a full microtransactions model, that may very well turn badly against them.
Also, if it is of interest to anyone: In the FaQ thread in the Solomon Forum, Jagex said they would neither remove SoF nor introduce any stat'd items, xp boost or other advantages to the store. Let's see how long that holds...