Think you are being harsh.
Pulis is showing what a good manager he is even if his players play very close to the line. Look how well brom are going and his teams consistently improve even if they stagnate at mid table for a while.
Allardyce on the other hand has shown he can stabilise and keep clubs up. If that is your target why wouldn't you keep with him?
The ones that are chronically crap and are on the merry go rounds are the ones that should get binned off. Your pardews, your dowies, your bruces (at least at PL level)
Newcastle and Hammers fans would probably have a different view on Allardyce and I hear plenty of Brom fans on phone ins moaning about Pulis. But both are good at what they do and keep their chairmen happy. Not saying they are rubbish or great. Just saying that the job they do suits the goals of many premier league teams, which is to keep such teams in the league above all else; hence why they always get a job.