Well, rumors have floated that Ellen was a tyrannical bitch behind the scenes. Then there was an investigation by the parent company into discrimination, including racial discrimination, I believe and abuse of staff. Now it's reported that she wants to leave the show, but there's a huge contract for years to work out.
I've just gleaned this from skimming headlines and the odd article, besides knowing she is a bitch to staff, tho that's hollywood. Not deep into it but that's the guist, and I enjoy when hypocrites get called out.