Your view of the Avengers seems to be less than most fans of comics and things like that I have heard. As far as comic book movies go most of them think it did pretty well. What were the parts you found the most lacking it?
As far as female comic heroine movies go I think some of it is that they might not put as much effort into it, but there also just hasn't been that many of them that involve major well known heroines. Electra also came out when a bunch of crappy comic movies were coming out so that move sucking wasn't that unique. I think in pretty much any medium Wonder Woman has almost always been a special case. From what I have ever heard she is just incredibly hard to write for and do good plots for a wide variety of reasons where even the best writers in the industry seem to think it's a hard task to pull off. She's one of the most well known comic book characters to ever exist, yet also seems to always been in the background somehow. Pretty nobody but the most die hard comic fans could probably even name off one of her primary villains, her origin (whatever the hell they have it as now), or a major plot she has been apart of for instance. It's telling that the most notable thing that the character was ever involved with was a television show way back in the 70s. I keep thinking they continually mess up with her because people either try too hard and try to completely reinvent the wheel with her or go to the other end where they just don‘t care. Probably her being thought of as existing partially for the sake of eye candy, and being that way for much of her existence, doesn't help the situation either.