Seems to me based on casual observation that snapshooters use them and serious photographers (especially pros) do not. I suspect this is because the snapshooters are told by the salesperson at the camera shop that they have to have one.
Wow, did you really think about this before you typed it? Rienzphotoz already responded with a perfect reply to your statements, but I just had to add to it. Statements like yours make
you sound like the inexperienced snapshooter. Of course I have not clue as to your actual experience and quality of work, but your comments can often give the inexperienced photographers the wrong idea. Please don't make grand assumptions based on casual observations.

My opinion based on decades of experience:
* Cheap filter is worse than no filter
* No filter is sometimes preferable in certain situations
* Quality filter is often needed for protection (sand, salt or fresh water (splash or rain), ice, dirt/mud, photojournalism...)