Because, it takes a long time and a long long grind to get stuff and build stuff so you can craft stuff, and its more than likely you dont just have another full set of upgraded armor and weapons to replace them and you are a bit from your base, and so its a huge tedious slog to just get your stuff back. Its quite painful, but that is the nature of this game, can be brutal at times.
I learned early to have a spare set of troll armor and stamina potions at my "forward base" always. But the loss of skill penalty is what really bothers me