One would not be justified in disliking a console due to three bad gaming experiences.
It's a huge inductive leap to say that the PS3 has no good games based off of only 3 games as evidence.
The fact that your friend loved a game (MGS)would seem to further invalidate his statement.
All he is really justified in saying is that in his opinion only 1 out of 4 games on the PS3 are worth playing.