I agree, I don't really mind very high difficulty though, what I do mind is a lack of intriguing problem solving within that difficulty. I find that the original Xcom's difficulty was more because of random map generation (and time of day) than the opponents. Getting landed directly in the middle of the map with an exit facing 5 enemies was "xcom".

That was fine, it was interesting and brutal. If you got a landing at the edge of the map in the day time you'd be able to do what you do in Xenonauts and carefully move across the map covering everyone safely.

Put players in the middle of the map, or create more interesting aliens who do interesting things that force the player to do some crazy strats from time to time. Let's see some sacrifices made by marines that pull the pin on a grenade and go down fighting, or landmine usage, or other weird things.

You can't get the really really interesting stuff to happen without truly random maps. Xcom's terror missions shined at that. Xenonauts doesn't. I'd argue newer xcom gets it a bit better, although it too suffers from chronic "play safe" mentality and only covers this up by giving the player time-based objectives to pressure them. A far better way to push the player would be to put more interesting aliens in the game that do things that are non-traditional in combat expectations.