1) I deny the underlying assumption of this thread; the design of a game, including its combat system, does not mysteriously deteriorate with age. Standards might not remain the same over time, but that is because they are inherently transient - the current design paradigm is as evanescent as any other. There is no objective metric of quality (of design).
2) While I am by no means averse the great power of storytelling (in) games, I am loath to entertain the notion that any game, particularly one as play-centered as FFVI (or VII, for that matter), could be expected to stand the test of time if its core elements failed to support the overall structure. The game-play of VI might be flawed (nothing is perfect), but not in a way that ruins the fundamental experience (setting aside the fact that VI actually has quite a deep and sophisticated combat system).
3) I direct you to others, who, I feel, have already adequately illustrated why your reasoning with regards to the specifics of VI's purportedly 'broken' game-play is terminally misguided and ultimately fallacious. Pro-tip; want to do something other than spamming attacks (adding an element of timing as well as additional strategic depth to a battle)? Try using Runic.