It isn’t really a matter of a good screen going bad, as much as a bad screen being used. Bad screens are just…bad. If allowed onto the press they affect print quality.
Print quality is usually broken down into two areas: resolution and ink deposit. However, one area that is over-looked in many shops is repeatability. It’s important if you ever have to repeat a job. You should always know what mesh is used, the tension, what emulsion is used, the EOM, and the exposure. It’s also not a bad idea to know what press it is to be printed on.
If you aren’t making good screens consistently, repeatability is impossible. That means, in the big picture, even a good screens are bad.