Philosophical beliefs in the realms of politics, social, religious, are long thought not to be a discovery of the truth but a creation of a system in which the believers want to live in. It is not true that "thou shalt not kill" in the sense that is is not a law of the universe, but it sure makes living together a lot more desirable.
The https://en.wikipedia.org/wiki/Is%E2%80%93ought_problem - discovering a cronyism might generate a knee jerk reaction to eliminate it without understanding the full consequences of doing that. The data involved in a problem is practically infinite. Better the devil you know might be exemplified like this: sure, Bob is kind of lazy and he costs you 5k$ to employ him at you textile factory, but outsourcing your production to Asia, even though 1/5th of the cost for same productivity, might introduce problems you are not aware of at the time like: child labor, local workers not affording to buy your products any more, the outsourcing company controlling or taking over your business, etc.
So just discovering a belief isn't an universal truth or that it generates some problems does not necessarily justify destroying it.