You know I see one of the biggest reasons people don't want Gwen back is that she was a boring character. I would agree that's true but if you stop and look at the time she was written it was at a time when super hero Girl Friends were boring and not much was done to develop them as characters. I mean look at MJ during that time. We knew she was a party girl who had liked Peter and liked Spider-man and she had an Aunt Anna. That was about it. It wasn't till after Gwen died that they really started to develop the MJ character and frankly it wasn't till they decided to bring the character back after they wrote her out of the books for a while that we even learned her back story.
Also Gwen was around for less than 100 books. MJ has been around for over 1,000 if you could all the issues of Amazing she's been in along with all the other Spider titles shes been in over the years. Of course MJ's character is going to be developed more.
Yes since Gwen died they have gone back and flushed out the character more and frankly I think Emma Stone/the writers of the movies did more for the Gwen character than any comicbook writer has ever done for her. What's wrong with that? She was around at a time that those characters weren't developed so writers have developed her after the fact. I don't have a problem with that.
With that said, the most meaningful thing Gwen ever did was die because of the impact it's had on Peter over the years. Her death was so powerful it's still impact the comics 40 some years later. It ensured she will never be forgotten. You could argue outside of Uncle Ben and Bruce Wayne's parents her death was the most meaningful in comics. There is something about her dying that has made it some powerful and it's not just because she has stayed dead. Her dad also died and has stayed dead and yet his death doesn't have nearly the meaning to it that hers did. That and the fact that it's 40 years later and some people still want her back and most of those people weren't reading the books when she was around (which means people had to go back and learn about her) tells me that there is something about her that made people care about that character.
I've said before I am all for bringing Gwen back IF you can find the right story to do it and the fact that no one has been able to come up with that story in over 40 years tells me that that story isn't going to be easy to tell. It also tells me Marvel and the people who write Spider-man understand just how important her death was and they aren't just going to bring her back for the heck of it. Anything done to bring Gwen back would have to not cheapen her death and frankly I don't know if that story can be told.
I will also say this if we are going to do a Gwen comes back story I want the real Gwen to come back. Not another clone story. The clone thing has been played out enough. I am not holding my breath on her coming back anytime soon. Frankly I think it's more likely that MJ and Peter get back together than they bring Gwen back. I also do think they will put MJ and Peter back together as a couple at some point (maybe not married but dating) because I think MJ has become Peter's destiny. Any love interest they have tried to give Peter over the years (including Gwen) has always lost out to MJ and not just in the stories but with the fans. So I think it's only a matter of time till MJ and Peter find their way back to each other.