This just points out one of the hidden assumptions that people make when discussing difficulty: the assumption that everybody means the same thing by a 'difficult encounter'. For one person, 'almost dying' on level 47 means that the game provides a satisfactory challenge. In my own case, if my character isn't frequently dying, it's not hard enough. That's an entirely subjective preference that can't really be standardized in formal rules.
Yep. Personally, if I was "frequently dying" in a game, I'd think that something's wrong with the game - either it's balanced incredibly poorly, or it's not the game for me (part of why I have absolutely no desire to go near the Souls games).
Dragon Age:Origins had several cases of "frequently dying". At first on boss fights, and then on various random fights. I started out turning the diff down to low for bosses, and then finally just left it there.... the combat was getting incredibly tedious anyway - only reason I wanted to keep going was for the story. (It didn't help that I had what was most likely a very non-ideal party. No mage AoE, for one. Shale, Wynne, Leliana, and my rogue.)
Gimping = choosing to limit your character to something less than the best they can be
I've mentioned before in other threads.... I don't naturally do the whole min/max, "best you can be" thing when I play games. Never done it in PnP RPGs, nor in CRPGs. I have to research and force myself to play that way (similarly to how, apparently, you'd have to force yourself not to). In most games, it's not a big problem. In games that are designed specifically for that style of play (D&D Online, Diablo 2 at higher difficulties, Sacred 2, etc) it can cause issues. Not everyone has "squeeze the best out of the system" hardwired into their playstyle.

(heh.... it reminds me a bit of my undergraduate Shadowrun campaign - I accidentally ended up making a character that was too strong... actually managed to find some of those "best combinations" of skills/etc. So I retired the character and made one that wasn't nearly so combat-centric. Was much more interesting.)