Although I agree that it would be best for an UX designer to make such decisions, most of the time one is not involved and there has to be some sort of limit ba

Although I agree that it would be best for an UX designer to make such decisions, most of the time one is not involved and there has to be some sort of limit based on some standard. If you allow potentially bad decisions, then ultimately a great deal of bad decisions will be made. For example, look at how browsers will render absolutely awful HTML soup and the state of most of the HTML out there.