I agree anime's don't have to have fights, MOnster as you pointed out is fantastic. I did a top 20 list of my favorite anime and that was my number one.

That said, Attack on Titan has a lot of action in it, Monster does not. With a higher focus on the action, how good it is has a bigger impact on the show. Most of the titan fights are just watching people zoom around looking flashy, and that happens over and over until the Female Titan Shows up.

And I would like to add that when Monster does have action scenes, they are always fantastic.