F2p is just terrible for a lot of games. SWTOR sub system failed because the game was a failure, they invested a lot of money into the game and started out with a massive amount of servers and eventually people started quitting because they became bored which made for less people per server which cause more people to quit. PvP in the game wasn't fun, and endgame raids ruined the game for most people, if you weren't in a guild and part of a core team you were not able to participate in most end game content which is another reason people quit. All of this caused them to switch to ftp so they could try and get more people back to the game and make money off the cash shop and charge for access to content.