This might have been asked before by others, but let me shoot it again: what is the ultimate purpose of GTO play?

Let me elaborate a bit.  Let's say we have K2o in BB and flop comes K96hh and our opponent c-bets.  I have a feeling that if we x/r K2o here, that might be more +EV than x/c'ing it in a vacuum for whatever reason.  However, if my opponents know that I x/r every King here, he can exploit it by a) 3betting on flop for thin value, or b) barreling wide when I x/c because my range is capped to mostly 9x or worse.  That will result in me losing money with other hands, so it kind of feels natural to think the GTO strategy should suggest I have some Kx in my flatting range.

However, I'm not sure if I really understand why.  

They usually say I can "protect" other hands in my x/c range, but I don't quite get it either.  Does it mean I can play those "other" hands more profitably, at the cost of playing K2o less profitably to a lesser extent, so that the overall strategy becomes more +EV?  If this is the case, am I correct in understanding that GTO allows us to play our overall range in the most +EV manner, but not necessarily each individual hand?

A slightly different question is, I hear lots of people saying "this is exploitative play but I'm gonna make it" in order to maximise profit, for example betting really small on KK2r board.  Now, what happens if they play every hand in their range in the so-called exploitative manner?  Do we ever lose money with any of those hands?  Well, I doubt it, because if we did we wouldn't have used the exploitative strategy to begin with (correct me if I'm wrong).  But if we switch to GTO, now, do we win more money with any of these hands compared to when we play exploitatively?  Or these are really the same thing and I'm just confused at the semantics?

At any rate, going back to the K2o example: if I want to x/c K2o instead of x/r, should it be because I think that's the most +EV way of playing this specific hand?  Or most +EV for my overall range, even though it might be -EV for K2o?