Well to be fair, all of the AC games have been easy But, I can see your argument even if I don't necessarily agree on some of the other points. I mean like I said, gaming tastes are completely subjective. As an example, I don't believe i'll buy BF4 because those type of games just aren't my thing now - that genre is so old, so very very old and tired at this point. But I'm about 99% sure that it'll be a good game even if it's not to my liking.
I understand why you say what you say. It (AC3) is certainly enjoyable, but not as much as AC2, for example. Assassin's Creed is already starting to feel a little tired and a little too "lowest common denominator:" too much fighting, which is too easy. Plus, the biggest advantages of a mouse, panning speed and precision, are removed because of dumb locks on panning speed (play AC2 and then Brotherhood to see what I mean. The sensitivity is WAY down) and weird "fixed-angle" moments all the time. It caters to console gamers, who have higher control than WASD for movement but a harder time aiming around. Then there the relative plot symplicity compared to the first game, and moral decay.
SPOILERS FOR AC2: Particularly, I feel like in AC3, Connor fails to fight for freedom of thought. In AC1 and AC2, you fought for an ideal. The maturity can be seen as Ezio does not kill Rodrigo, but leaves him alive because killing him will do nothing to bring back his family. This is a huge change from the rash teen who swore bloody vengeance on the Pazzi. There is a central pillar of morality where we see that even though Assassin's are inherently murderers, they are discriminant in who dies and fight for freedom of choice and thought.
In AC3, we see instead an angry man out for vengeance and to protect his land. It's pretty good reasoning, but Connor seems to have lost the noble, higher sentiments that guided older Assassins. His primary tool is brute force, and he lacks the finesse and political savvy of earlier protagonists. Many of his targets appear more sympathetically than Connor, especially those trying to bring peace. He also ultimately fails: the colonies still have inequality, his people moved, and he never seemed to reach a cathartic moment of understanding or balance.
Anyway, I'm feeling upset that the next one basically has nothing to do with a higher level struggle about ideology and morality. It's a pirate, for God's sake. Everyone knows that (pseudo-)ninjas and pirates don't mix.