The reason the person the OP mentioned are completily valid IMO. Game music music has much in common with film music, and they differ from classical music in that they have a purpose, namely building up the moods in the movie/game. Much classical music is much more complex, and is made to work without any visual stimuli. Also classical (especially contemporary) cater to a very different, and smaller, crowd than movie/game music. Game music tries to cater to everyone, thus makin simpler music everyone can understand.
What im tryin to say is that movie/game music is much simpler, and optimized to work well with its medium. Therefore those who like classical music may not like it, due to its simplicity, and the fact that it doesn't work that well on its own.
BTW, i am also a classical musician, and i love both classical and game/film music.
EDIT: One can compare playing music without its movie/game to playing music without its lyrics.