And I can add another 9 to yours! Not that that has much to do with anything though.
However, coming from a film camera background I grew up using UV and Skylight filters and still use UV filters on most of my Canon EF lenses today, as I also use these lenses on my 35mm EOS film cameras, plus a filter completes the weather resistance of some of my Canon 'L' series lenses (something that hasn't been mentioned yet?).
The only time I would definitely remove a UV filter is if I wanted to take photos of the Aroura Borealis, as the light frequency from that reacts with a UV filter, which causes a Newton's rings type effect on the image. Apart from that I'm happy to use them, after all, if I noticed some flare or ghosting when taking night shots of bright street lights, etc. I could soon whip the filter off and try the shot without it.
As for the protective effect, I believe that a good quality UV filter can protect a lens against impact, and save the front lens element from getting accidentally scratched too. Plus, a scratched or broken UV filter is usually cheaper to replace than a front lens element. Years ago I was shown a broken UV filter that had a stone road-chipping embedded in it, it had come off a zoom lens someone was using to photograph a special stage on the RAC Rally. Fortunately the chipping had been caught by the filter and hadn't touched the front element of the lens, so after removing the filter with a filter wrench the lens was found to be undamaged. Without the filter it's almost certain that the front lens element would have sustained sufficient damage to require replacement. Yes, it was lucky the chipping hadn't touched the front element, but without the filter it certainly would have done.
As others have said though, using a filter is down to personal choice and is not compulsory, so I'm sure you can all make your own minds up.