After MASH was an example of a network getting greedy, MASH had the good graces to end after a whirl wind event night on television, it went out with a tremendous bang. It should have ended there but of course, there might be something to be mined from the characters and the premise.
So, they gathered up whatever stars they could from the original MASH and used the premise that Colonel Potter, Sergeant Klinger, and Father Mulcahy find themselves together once again, this time at a veteran's hospital.
The results were mixed, all of the guys were great on MASH but without the other characters it came out rather flat, the show tried to exploit it's connections to the original series as much as possible even RADAR made an appearance but in the end it was all for naught.
After MASH limped along for another season before being cancelled, it was good but not great and certainly not the worst "post-sitcom" ever created. That my friends, likely belongs to "Joey".