So lemme get this straight...
Smacking the lens face with a claw hammer MIGHT damage it if you hit it hard enough but a couple sprinkles of shattered glass from a filter will spell its doom.
Smacking into something accidentally MIGHT cause damage to the lens threads but accidentally smacking the lens filter into something will so irrevocably damage those threads that the lens will be unusable if you then remove the filter.
Lens flares and halos will just JUMP out from your images if you're foolish enough to use a UV filter.
I now know what caused the tsunami in Japan that wiped out billions in real-estate an toppled one and half nuclear reactors. All those Japanese were out taking pictures with lens filters!
Seriously... The REAL advantages of a UV filter do not include impact resistance. You install a CLEAN filter over a CLEAN lens to prevent micro-scratches. A good UV filter will cut haze both indoors and outdoors. High altitudes and/or pics near water or humid conditions will all be improved with a UV filter. The exception would be that guy that tossed a $10 filter from Walmart or Bestbuy onto that $2000 lens that was mentioned above. Like anything else, there's quality and garbage alike to be had. There are also different grades/gradients of UV filter that depend on correct selection for conditions.
A QUALITY UV filter is worth it's weight in gold for either film or digital cameras though the reasons differ some between the two.
If you've been taught to believe that, that's false, you may want to consider listening to someone else. It sounds a lot like something rationalized by one person who's trying to frantically spread his gospel (photography teacher maybe). Fact is, the benefits outweigh the liabilities by pretty large margin with exception of the most controlled environments under carefully metered conditions.