That does make sense, sure.
I think "dumbing down" Alan Moore would work about as well as those lousy "easy reader's versions" of people like Herman Melville and Victor Hugo. In other words, you've gutted it and then handed the carcass to people and expected them to appreciate it.
Personally, I don't have a problem when Hollywood "adapts" or makes over something. When I dislike a comic book based movie, people (friends and family included) always assume it's because I'm familiar with the original comic and it wasn't like that.
The thing is, I thus far have been familiar with the original material for most of the comic book movies, but that doesn't hold me back. Batman Begins, for example, wandered way away from most of the comics and I enjoyed it immensely, because it was well acted, well written, and it took itself seriously.
That's all I need. I don't care if its entirely faithful.
With Alan Moore's work, I go back and forth. I respect that he had his name taken off the film credits and had his share of the money split between the other co-creators. I was less than thrilled about the huge media stink that was made about it (none of which came from Alan himself, who is a quiet and sweet man). Alan Moore snubs Hollywood, hates Constantine! garbage like that.
I did not like LXG, because it was shallow and it acted silly. I disliked it for the same reason that I disliked the new Star Wars movies. I expected it to be changed and adapted, but not turned into a "teen titans, but with really old characters from books" sort of movie.
Inversely, I enjoyed V for Vendetta very much, even though it was written by the Wachowski Brothers, who have a less than sterling reputation for being able to write (Matrix 1: Good. Matrix 2, 3: Not so much.) I thought it was well done, powerfully acted and written, and gave me brilliant and moving performances by Natalie Portman, and Stephen Fry (he made me happy; he broke my heart).
From Hell was less than perfect. It had good moments, the ending not among them.
I enjoyed Constantine, though it had none of the depths or character that the comics had. It wasn't bad. It wasn't great either.
The nice thing about movies is, if the movie is good then it helps the book. If the movie sucks, then the book is untouched and unaffected.