The argument about subs for online games being a rip off always make me laugh.
Especially given that even a small MMORPG (by modern standards) can require multiple high quality/reliability severs per shard/realm/universe, a team of game designers, QC people, tech support/specialist server support*, the subs/out of game support team, and the in game support (GM's).
Games like UT can't be compared to MMORPG's in that an FPS has zero "memory" of what you've done normally, has a very limited number of players at a time, and a massively limited number of objects to keep track of/interact with, and no real development after release apart from the odd patch or minor update for the first year or two (TF2 source seems to be the exception to that rule).
With MMORPG's you tend to get new content on a regular basis (so they can't dump the dev team), regular patches, massively complicated server setups that might have to track thousands of items per character** (and you might have 5-6 character per account, per realm/shard), and keep track of everything potentially for as long as the item remains in game, or the server is kept running - I know of players in UO for example who still have server birth items from over 8 years ago.
You can end up buying an MMORPG and not buying another game for years because of the size of the game, and the fact that with a good one you'll never really run out of new things to try out, or new ways to do something you've done before (for example in UO there are about 50 skills, with obvious groupings for certain character types, but older/more experience/adventurous players have been known to try taking on high end monsters with "unusual" characters such as a stealth/herding/cook/bard, rather than the normal tamer/mage/bard, or axe/healer/warrior).
In the end it comes down to personal preference, but economically speaking it can work out much cheaper to play an MMORPG, even at the higher end of the subs range(£10-15), than it is to buy just 3-4 games per year that might only last you 30-40 hours each if you're lucky.
It's certainly one of the cheapest ways to entertain yourself in terms of price per hour.
And to be totally honest, i'm still paying my subscription for UO, and have been for a couple of years despite not playing it much these days - I pay because I still get about the same amount of use out of it per year (probably a couple of hundred hours), as I get out of most other games I buy pound for pound, and I am rather attached to my in game house
(I ran it as a tavern for a couple of years and it's got a lot of very fond memories, which is daft).
*IIRC some of the older ones are using code for which only a handful of people are familiar with it (I believe UO for example uses an almost completely custom code for parts of the servers that only a couple of people know well).
**UO for example lets you have 6 characters per normal shard, about 25 shards, each character can have 125 items in their bank box + another 125 on them, and one house per account with up to about 2400 items in it, not including the customised house itself (which might be made up of several thousand tiles).
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