> There is probably no harm in checking your database for such columns

The harm is the same as any other unreliable linter rule.

Each one such rule is almost harmless. And on most places that use that kind of rule, they are extremely harmful.

With that I agree, once you start to treat the output of any linter as the truth, you are actively lowering the quality of your codebase. At the very least if it has reasonably good quality, if it is in bad shape, blindly following linters might still increase code quality, you will just not reach the peak.