I might be missing something here, but isn't hiring somebody new to do your job exactly what the new owners of the company have to do if you sell it? Maybe this will be delayed by golden handcuffs, but sooner or later it has to happen.
If you sell it you won't be hovering over whoever gets placed in your position to tell them how to do their job and technically it is now the buyers problem, not yours.
Bill Gates did it with Microsoft and at that level I'm sure that there is enough momentum in the business to keep it moving along or even to improve. But most smaller businesses (say < 30 employees or so) are both culturally and dynamically much more personal and being both gone and still present in the background creates a strange power dynamic (who's the real boss?) and frustration.
