Almost never. In 2004 when I created my best map at the time, an RPG that I spent a long time making and that I felt passionate about, I played it with all my family and everybody had a copy but it was my first time protecting a map and I kept the unprotected one only for myself, planning to make updates and keep working on the map for years to come.
And then one night we found out the hard drive died on the computer that I used most frequently. We had a backup of the Warcraft Maps folder on a different computer but I had made sure the backup didn't include the unprotected version, so that only I had the unprotected one.
And so I became stuck in the horrible world of no return where I could play this map I had made and I could see the bugs in it and I could never fix them. Eventually I ripped apart the map and remade every single trigger by hand because I didn't know JASS in 2004 and would not have continued to enjoy developing the map if I had to deal with complicated scripts that I didn't understand.
I went on to develop that map for years after that and eventually forgot the whole fiasco when I reached a point that the new version was infinitely better. But no, that was generally my first and last time protecting a map.
I think that more than a dozen years later in 2017 I tried out a map protector when it became clear to me that I should put the Heaven's Fall altered melee mod I had been working on into a map to keep it running on newer game versions. I thought protecting the map version of this mod would make it seem more official to people. That year and in the years following, patches came out that added 24 players and basically destroyed the playability of any protected maps, since the idea of map protection is basically a joke that revolves around file corruption and obfuscation. So then I started playing the unprotected version of my mod-dumped-in-a-map with other people anyway because it was the only version that worked. And, as I suspected, I never saw anyone bother to modify it. Nobody cared that much, we were just having fun playing the game. Admittedly I would most likely have been flattered, not upset, if someone actually did modify it.