I can understand why critics didn’t like the movie!
There are pretty much 2 causes for the answer of this why:
1. G.I.Joe is action packed and overflowing with clichés, (just like the cartoon). I guess critics must have forgotten that.
2. Some scenes did look like they were quickly put in at the last minute but there are just too many characters to develop and not enough time.
The critics that have a problem with that should remember one thing. This is a movie based on a cartoon that's sole purpose was to sell a set of toys to 5-12 year old boys. So the movie would obviously be made hat type.
I agree there were many flaws, as it not expected to be here, but it entertained. And I think that’s what after all matters to the audience, but yes not to the critics.
Overall G.I.Joe is funny, has great action scenes, and keeps to the roots of G.I.Joe enough to be considered a great movie. Audience, go for it!