My sister did, and unfortunately she didn't even re-sub as soon as I told her that the expansion was locked behind main quest (and unlike her I was already done, so I couldn't even accompany her, except for dungeons).
Fun fact: she actually followed the story - unlike me who skips everything. She just found the quest locking annoying and didn't want to feel forced to do story bits just to unlock dungeons. I remember when she got super annoyed that she was nearly 30 and still didn't unlock her first dungeon, until I said "did you do your MSQ" ...her reaction was priceless!
On the other hand, a friend quit the game at level 12 because he couldn't stand the voice acting of the game (not even the story itself). A bit harsh, but he's a big fan of SWTOR story telling so for him this was a massive downgrade.
