Wasn't Mr. Yentob one of those involved in "Doctor Who"'s axing in 1989?
It makes sense that a suit would want the show axed
Everything I've read suggests series 3 would have been great. A shame it was never to be

According to John Inman, the controller of BBC1, Alan Yentob, was not a fan of the show and wanted to move the channel in a different direction, and so would not commission a 3rd series. I don't think the cancellation had anything to do with Billy Burden's passing. He was a fun character but not essential to the show. The proposed 3rd series, according to Inman and David Croft, would have seen Mr. Humphries and Mavis get married (which wouldn't been a problem in the absence of Mr. Moulterd, as this could have been worked into the story, perhaps a lonely Mavis seeking comfort with Mr. Humphries after the death of her father). Mavis was also apparently going to then run off with a farmhand and leave Mr. Humphries devastated. The other major storyline in series 3 would have been an appearance by Mr. Lucas (Trevor Bannister), perhaps in a role-reversal from AYBS?, with Mr. Lucus now a wealthy businessman interested in investing in Millstone Manor.

I'm not sure that everyone concerned wasn't just a wee bit weary of it by then, even though a few years intervened between AYBS and G&F, and the latter having only 12 episodes.
"In my case, self-absorption is
completely
justified."

OK, that was in the script, but I wish they would have appointed another to run the farm.
Probably, Burden's portrayal of Moulterd was so over the top, they couldn't find a believable replacement.

Mr. Moulterd didn't own the farmthe Grace Brothers retirees did.

It is my understanding that in 1994 Billy Burden (Mr. Moulterd) died suddenly. Evidently he was such a central character, they couldn't replace him. (Why not a brother or other relative who inherited the farm?) Too bad.