I doubt it has anything to do with turn-based battles, but boring battles. Regardless of story or whatever supposed to be a unique selling point of RPG game, 90% of time you're battlling someone, thus battles is regular gameplay for electronic RPGs and should be fun.
Though Mr. Horii has noted that "more startegy" involved in turn-based gameplay, but usually it's not. Sid Meier once said that "game is a series of interesting choices", but in great majority of turn-based jRPGs either choices are trivial or they really don't have any actual effect on end result (choose attack or whatever magic you have, there're no substantial difference, just don't forget to heal yourself). The good indicator of bad gameplay is if auto-battle is being used (or you're spamming one button while in battle), it means that player is avoiding playing boring parts of the game. In some games things are getting better in latter parts of the game with more unique boss battles and more party members to choose from, but usually I won't play 20 hours of boring game just to experience smth marginally better afterwards.
Of course, there're people who'd like to torture themselves with grinding, but I'm not one of them. But Mr. Horii is still wrong, I play turn-based and action-RPGs equally (Eschalon: Book 2 and Mass Effect 2 lately to be precise), but usually I won't enjoy turn-based jRPGs because of the things mentioned above (some notable exceptions are Personas, Fire Emblem series etc.).
