Re: What didn't you like about the film?
^ Yes, we had aliens attacking Earth in the Avengers. But name another super hero movie where a horde of aliens were the main villain?
I don't think there has been...
So we don't compare a super hero movie to a non-super hero movie, do we? So your whole Mars Attacks or Independence Day doesn't hold water...
The point is if the main villain in say Justice League is a horde of aliens then yes, some of us will come to the logical conclusion that it's a bit of a rip off of Avengers. If the next main villain in Batman was some dude that wears a suit that looks like a rhino, well yes we'll logically conclude that it's a rip off of Amazing Spider-man 2.
As you say, much of the issue is how it is portrayed. Since they used a mech suit in Wolverine and had the guy shown in it with his head shown well of course there will be comparisons to Iron Monger, and rightfully so. Especially when it is such a divergence to the comic canon. Making the Silver Samurai a mech... bleah!!!