They developers were quite aware of the capacity to cheese fights. I quickly learned that trying to gain elevation to fight animals was just an invitation for them to spit globs of crap at me.
Yes, that was a nice surprise, in particular, because the very first enemies like rats, biters or raptors didn't do that. So for a while you think that you can cheese the enemies not only with the jet pack but also by climbing to higher terrain, which the enemies couldn't reach and then use ranged weapons. But then you got a small shock, when the third or fourth enemy type you encounter, spits at you and it hurts more than their melee attack…
That was a clever design idea and made you carefully plan you approach, in particular if you are a ranged fighter type, which I always prefer to play.
That reminds me that in the Gothics you could climb on a rock or a house and shoot the orcs etc., because most of them had no ranged attack…