Because it's popular to make snarky comments about something that's a perceived threat.
TOR is going to be a big hit, because it has a lot of WoW-ness to it. Not that it is WoW in space or any of that garbage, but if people enjoyed WoW, and are looking for a similar experience, but with better presentation, they'll like TOR. Of course there will be people that don't like TOR that love WoW, because they either hate Star Wars or Sci-Fi, but that's understandable.
GW2 doesn't cost a monthly fee. Some people can't get past the fact that you buy TOR now, pay your monthly fee, and when GW2 comes out, you plop down your 60 bucks like every other game and woah, look out, you can play that as well. I'm sure plenty of people will. It looks like it's going to be a fairly good seller out the gates. Sort of like they do with WoW now. They pay their $15, but they still buy, gasp, other games, oh noes, you can play several games at the same time, imagine the concept.
GW2 has far more to lose in the long run. TOR hasn't promised a dang thing they haven't delivered on, which was the failing of more than a few MMOs along the way. They'll have plenty of subs, with plenty of bang for your buck, in a popular setting, with a company that can deliver with a re-imagination of the most popular MMO currently. GW2 is trying to do what a lot of other companies have done, and reinvent the wheel (I love clichés!) by "removing" the trinity (they still have it, just in a less conspicious form, regardless of whatever mumbo jumbo they try and spin people that heal better, and people that take damage better and people that DPS better) and essentially making a giant solo game.
I'm sure GW2 will do fine since there will be people that want a solo game, with a flat leveling scheme and they never have to interact with a single other person if they don't want too. They can PvP to their hearts content. I just hope they don't expect some shining example of endless gameplay that's not going to happen. No money rolling in = less content, unless the Arenanet guys are happy working on the next expansion gratis. You'll never know how well the game is doing until expansion no. 1 comes out and you get to see sales for it. They can claim "we have X million subs!" since no one ever "stops" subbing to the game.
GW2 will do fine, but to think it's going to be some giant success (aka bigger than WoW is/was) and that F2P is the only game is town is a bit far fetched. TOR will do just fine, as long as the BioWare guys keep dumping out quality content. WoW, TOR and GW2 can coexist all together in one little package, with people that play some or all of them.
Tera however, is going to do the dead fish flop. The Secret World I wouldn't touch with a 80' pole. Those two, I'd avoid like the plague, since they already have failure written all over them.