I think Xavier was engaged in a vast conspiracy to prevent Jean from every accessing her full powers:
1. Xavier blocked Jean's tragic memories instead of helping her come to terms with them.
2. Xavier blocked Jean's telepathy
3. Xavier restricted Jean's telekinesis
4. When Magento captured the young Emma Frost and tried to user her to weaponize Cerebro, Xavier put Emma Frost back in the asylum instead of letting her join the X-Men. Probably to keep her from reading his mind and keep her from unblocking Jean's powers and memories.
5. While Emma was in a coma, how do we know that Xavier didn't meddle with Emma to make sure Emma never tried to help or work with Jean.
I am sure I could come up with more stuff, Xavier is creepy, especially with female telepaths!