Was bringing Scott back a mistake? No. Killing him in the first place I would say was a mistake. Making him turn into Dark Phoenix was a dumb idea. Having him kill Xavier was bad in my opinion. The mutant hitler bit was beyond the pale, but I think rightclops fans must move on form it. Scott had a complete arc and he became a complex character which is good, but there is a down side when characters kind of take over the entire (or most of) story.
I've always loved Cyclops but at times he could be a bit dull. Scott became a great character under Morrison. I loved what Morrison did with Scott. I was excited to purchase every issue of New X-men because I was so eager to see the story for both Cyclops and Jean Grey. In regards to Scott, Whedon took the ball and ran with it and further developed him. Then all the other writers continued the saga of Cyclops, leader of the mutant people: Brubaker, Fraction, Bendis etc.
Scott was the star of the X-men. It had became his story and I feel this is where it all went off the rails. The X-men has to be more than a story of a white straight dude. I like that Scott is captain commander but I think the books should be careful not to make it all about him. Scott is Xavier's general, but other characters like Storm, Jean Grey, Wolverine are also vital. I think when one character gets a huge push you see pushback from fans (see Kitty Pryde in X-men Gold, etc).
I do love the first two issues of Hickman's X-men but we've had years of the Scott show up until his death. We had what a two year break and now he's back to being Mr. X-man....the best field leader (which I always find disrespectful towards Storm who to me should always co-lead with Scott). I do like that Hickman appreciates Scott Summers. I like that they are putting his darker days behind him. I am glad so many fans can identify with him. I just hope those same fans can identify with other characters who may not be like them in the same way Scott is.