So I came across this issues today and I couldn\'t find some meaningful explanation is there some non-subjective reason to use static methods when it comes to database inter
I think your last statement is correct; its just the previous developers approach.
I will say, though, that having those methods static is going to make your life a nightmare to create a testable product; if you have the power to change them to be instance based and create a set of unit tests that can test the app via mocks without needing a database it'll make your life easier in the long run.