I'm tired of game designers thinking that it's wrong, or bad, or a poor design decision, to allow players to encounter problems they cannot overcome, especially in an open world game.

Some places are dangerous. Players can deal with it.

The trick is to implement your mechanics in such a way that a player can disengage and escape even from a challenge that they're not ready for. The act of fleeing can be fun and involve interesting use of abilities, etc. It can be done, and has been. albeit not often very well.Look at your average MMO. Most of us have played WoW, and I'm sure we've all had those "Oh shit!" moments where we realized we were going to friggin die and had to turn tail and run. Sometimes it's PVP, in which case frantically throwing out stuff to slow down your enemy and reach safety can be pretty intense.

And that's ok.