I get the sentiment of hostility towards Ronaldo, but honestly pragmatically I think we need him to stay. We are desperately short of options upfront. There aren't many forward options available, and signing those that are is made harder when we're out of the CL. Sesko would be a nice signing but he'd be one for the future. There's more for us to gain by keeping him for a further season. He can help us secure a return to CL, we can work ahead to the next transfer window to secure a first choice CF.
Ronaldo's relationship with United has also been one of mutually beneficial one. We offered him the chance to play in a top league for a top side, we helped him on his way to becoming one of the best players in the world. He gave us a CL and three league titles in a row. Of course he developed affection for the club, but ultimately he had his own goals and aspirations which saw him pursue the move to Real. His return was a further opportunity for him to play for a top side, in exchange for a high profile signing for us and much needed goalscorer. We aren't a top side currently, haven't competed for trophies, so inevitably he would look at the possibility of moving. I wouldn't expect anything else.
Ultimately it seems it will suit both parties that he stays. There's not a better offer for him elsewhere, we don't have the time or ability to replace Ronaldo with the suitable quality this summer. So the mutually beneficial relationship will be extended for another year. It is what it is.