The disappointing performance of Star Wars: The Old Republic was not the result of a bad 'roll of the dice' or because the market is saturated with MMOs. It was because of a clear lack of knowledge and competency on BioWare's part to design a strong MMORPG, despite getting around $200 million thrown at them.
Firstly, any claims that SWTOR's failure to explode into a massive hit will harm the industry are not counting the number of MMORPGs that have been simultaneously available for the past 5+ years. Count the F2Ps, because they outnumber P2Ps by a large margin, though most may be virtually unknown by the majority of sub-model-only players (and regardless, the F2P MMORPG playerbase is plenty robust with new games coming out regularly, obviously because people are still interested in playing these types of games). By that metric, the MMORPG market is saturated with games at pretty much every point in time and has been for several years now, albeit with games of varying quality. Before WoW was released, nobody could imagine that the market for every MMO combined could possibly number in the millions of players, let alone the playerbase of one game. So apparently the situation here is more along the lines of 'if you build [a game people want to play], they will come'.
I won't rehash all the ways SWTOR was designed from the core out as just a variant flavor of World of Warcraft's basic gameplay mechanics, because that has been done to death in many places already. The fact is, in an environment shaped by 7 years of the dominance of WoW and scattered with the corpses of games released since 2004 attempting to ape WoW's success by copying it's gameplay to varying degrees, the majority of MMO gamers are just plain tired of it. And because they've become very familiar with the tropes of WoW's formula, they've also become a whole heck of a lot pickier when it comes to judging any game that tries to make it's own spin on it. So far the only game that has done this and succeeded has been Rift. So the right question to ask is not 'Is the market over-saturated with MMOs' but 'Can the current market support WoW and 2 sub-based WoW variants at the same time?' And the answer might just be 'no'. In the words of ArenaNet's founder Jeff Strain in 2007:
"Don't be fooled by the much-hyped success of the top MMOs on the market. The game industry is littered with the carnage of MMOs that have failed over the past few years. Due largely to the social nature of MMOs, gamers rarely commit to more than one or two MMOs at a time. This is in contrast to the traditional game market, in which there is room for many games to be successful, even within the same genre. You may play ten different action games this year, but you are very unlikely to play more than one or two MMOs. This means that it is not enough to make a great game – instead you must make a game that is so overwhelmingly superior that it can actively break apart an established community and bring that community to your game."He may as well have written that today, for all it's remained relevant (the only thing I would add is that it goes double for any game attempting to run under the '$15 a month sub fee' model nowadays). For anyone to conclude that the failure of games like Project Copernicus and SWTOR's lack of popularity means the MMO industry itself is in peril seems to forget that game studios being run into the ground because of poor management is hardly new. If anything it's showed that the MMO industry is not immune to the reality that exists everywhere in business: that throwing tons of money at a game (or using a popular IP) doesn't automatically mean it will be a smash hit. Any problem for the industry here is a self-caused one: disinterest in the playerbase because gamers are getting tired of companies rehashing the same-old ideas with prettier skins and expecting people to keep paying $15 a month to play the same game they've already been playing for the last 10+ years.
SWTOR bet the lion's share of their hundreds of millions of dollars on the premise that the way to outdo their competition would be to make individual class stories as interactive and cinematic as possible (since that is their studios' strength in singleplayer RPGs) and setting them as the core of the entire game, while simply copying 'what's worked before' for everything else. But they attempted to 'innovate' in the completely wrong direction because they lacked fundamental understanding of what makes a strong MMORPG -- the long-term replayability of a game's core mechanics, as well as underestimating just how tired many people are of those gameplay systems that 'worked so well for WoW'. So after their awesome single-player interactive movies were all finished, most SWTOR players looked around at the rest of the game, said 'meh' and unsubscribed.
Related Reading: How to Create a Successful MMO [GDC 2007]
Behind the Scenes of Star Wars: The Old Republic
Story vs Persistent Game