being jumped by 5 opponents completely distracted has a negligible chance of survival, regardless of engineers which, i concur, are a plague, and i never miss an opportunity to say that!
re learning ... indeed there is a learning curve it's just not what you think. no amount of experience will make a stock python escape 5 surprise stock gankers except sheer luck. (btw that's easily testable, if you're ready to be the prey i'm sure we'll have plenty of volunteers).
what you have to learn in this case is, as said, awareness. of what type of system you are in, what it's security is, what is going on there and who's there, specially behind you in your radar. if you were playing with sandcastles in an instance you surely got a message that someone dropped in, right?
there's your learning curve: learn to read the signs to survive in that environment. once you get to the point of being shot at point blank by 5 guys with your pants down, all that has already failed, it is either needs-more-learning or just bad luck which always can happen. the thrill of doing this in open would be zero if bad luck could never happen, right?
a kitten just blew up, you monster.
which albeit being a gross exaggeration really boils down to what multiplayer (interplayer?) experience the game can provide. the danger and distrust are a central trope, they play very well with the concept of a big, scary open world. so if you can get gutted for being careless, however tragic, that's actually part of the appeal.
maybe not your thing, but that's how the open world is. of course for those who want to do
undisturbed pve, without that thrill, there are the modes, and that's not inviting you to be antisocial. it's just giving you exactly what you want: the 'virtual world' without the 'social' (dangerous) part. careful what you wish for.