Just to let you know Jean's lack of character devolpment comes from one of three storylines CONSTANTLY being rehashed.
1) Love triangles. 35+years of and the only personal devolpment they have for her is to have her firecrotch in high demand. Are you kidding? No leadership skills, no personal skills ( being a failed model doesn't count as a skill), "Help me save me even though I am uber and unstoppable," no wonder why she has lead only one mission, quiet some time ago.

Let me see now...Professor trusting her to become the new handmaster of the school and given a speech for the first time to help fight for mutants.......Don't see no other X-men doing that before her did you?????....If you hadn't notice that love triangle died During GM's run...I wonder what you think of the Namor/Sue/Reed Love triangle???Spider-man/black cat/Mary Jane???? get the trend, a love triangle is a plot device......I like her being a headmaster of the school anyday and let scott do the leading.........even with no X-man at the school but children she was able to hold off an army just to protect the school....Professor can't do that at all and you couldn't get in the army's head.....Jean has many personal skills much more than any other X-men, Speed reading, Speech Techniques,Interpersonal skills and many more....
Birthing AU machine. Rachel, Cable (yes it's her clone's son, but it's still has her DNA, and X-Man.) Oy vey. Technically she's not even a mother because she hasn't raised a single child. And while I'm at it, I can put the whole obsession with her DNA in this category. How many times are they going to tell that story? So if that stays, then just for the hell of it, lets throw Maddie in this category. They killed her and brought her back more than once and they got rid of her when Jean came back. Was there a need to have two lookalikes who did the same thing basically both after the same man?
Jean been the mother figure to all the X-men and to cable....they tell the story uuummm because it sells......Maddie was introduced for scotts sake, why don't you ask Chris Claremont why he wrote the Imferno if you have issues with it, cause as far as im concerned I never liked it...they killed her so many times cause uuumm she's a pheonix..........Maddie died as for Im concerned.....Jean was still alive...and after that Jean/Scott fans were happy...and the adventure continued...they got married....but you can't stay happy for long in the MU
Phoenix-Lather-Rinse-Repeat. JUMPING JESUS, HOW MANY TIMES DO WE NEED TO READ ABOUT THE PHOENIX? The act hasn't changed enough to hear about it every three years. Outside of the deadredbird, how has Jean's character changed. Compare the development of Kitty, Scott, Colossus, Storm, Hank, Psylocke, Rogue, Gambit, hell even Bishop to Just-Jean. There is a monumental difference. Why, because the only stories about Jean are the ones I mentioned above. It's like no one has the ability to tell a story that doesn't revolve around things in her, or that want to be in her...

HOW MANY TIME ARE THEY GONNA PUT WOLVERINE IN FRONT OF THE X-MEN...DAMMIT DON'T THEY KNOW...THAT WOLVERINE SELLS....AND SO DOES PHEONIX!!!!...Jeans character has changed....alot.....some traits are still there...GM exploited a treat and it back fired on her.........None of those character have changed that you mentioned!!!!!!..all of them used recycled story arcs that are redundant........must of been interpreting what you read badly but whatever.....Psylocke,Rogue, Gambit, Hank, etc.....please!!!!...Hank changed you say....he got more fur!!.....How many times has plots been recycled with Rogue and Gambit again?????Bobby drake????.....he still acts the same way he started........what happened to the flirt/handsome playboy going after every girl he used to see..HUH?????????Pyslocke???????and you complaining about jeans Death!!!!Colossus and kitty changed???..Really!!!!...How many Recycled plots have been used in the X-men for the past decaded....Ressurections,Death,Same Villain doing different things,Rehashed characters..more love triagles,...Evil turns good, Good turns evil, Evil turns evil.......Moving on
We have seen X-men change drastically since their debut, but not so much for Jean. She hasn't been allowed to become a different or BETTER character like others because all that's written about her that has changed has been her *powers*. If that doesn't change then she needs to stay dead. Let her final sacrifice ACTUALLY mean something *this* time.
If she doesn't stay dead, please please please, let her have no Phoenix Force and no mutant genes. Let her come back completely human and start to be a better character. Maybe by having no powers she can learn to save herself instead of constantly needing a big strong man to save her when she's all powerful. It would be a great place to start to improve her. She needs to change, 25 years of stale storylines suck and blow like a malfunctioning Hoover.
Jean life change drastically when pheonix came in contact with her, she was the first X-men get drastically changed in the fist place then guess what....every other X-men went through the same thing.....we have seen jean have a split personality and don't know who she is.......Cyclops you say changed drastically.........yeah right!!!!! He been the same the same way he started for many years.......He been in love with Jean since he was a teenager....NOTHING CHANGED THERE!!!!!!!!!!!Stoic leader for many years....STILL NO CHANGE!!!!!!!!!......female Telepaths Always go after him and is never single.....NO DRASTIC CHANGE YET!!!!!!!!!!when Apoc merged with him.....Oh change finally came..........how many years did that take again?????...pretty long time.........I disagree totally with every single word you said....You must not like every other X-men if you saying that jean didn't change since she started because I could name a list of X-men that didn't change...........maybe every single X-men is the same to you........its been 40 years come on!!!!....characters change...Jean arc is on hold for now....