Course you can't argue about tastes.
And it's weak immediatly judge/rating a map as 0 if you don't like it.
But, if you happen to run into a map you don't like to play, you are free to comment on it. Just make sure it's valid commentary. Cause, what help does "omg sucks 0" offer to a mapper eh...
...
Though some creations do deserve a 0, without questioning, because they're so incredibly bad that only a handful of people could possible "like" them...
Not referring to this map...
But you know, they excist...