Look again...it takes the CLAW side of the hammer to make any noticeable impact on the front element. Besides, as we know, damage to the front element causes almost no noticeable degradation of image quality. You can cut a postage stamp in half and lick it and stick it onto the front element of a lens, and its presence is barely seen in the photos.
"protective filters" are basically a huge,huge profit center for photo dealers. I know this because I used to work for a large chain photo store; we bought filters by the case, verrrrrrrrrry cheaply, and sold them at huuuuuuuuuuuuge mark-up; that is the way filters are sold!
Does anyone really believe that a flat piece of coated optical glass in an 89-cent brass mount is worth $109 because it says B+W 77mm on the rim? There are many people who have payed big money for "high quality protective filters", and cannot seem to overcome their problems with cognitive dissonance on this issue, so they insist that protective filters really ARE a necessity.
I used to use UV filters, Nikon L37c almost exclusively, for years. I stopped, 20 years ago. No issues since. None. Not one, single problem.
Oh, by the way, I'm wearing a condom, right now...you know, in case I have sex later tonight. "Always wear protection!"