This is useless crap, because of 2 reasons:
1) Too far from farm spots, you must go back all the time with resourses and risking being killed on the way.
2) If i will choose who to raid - i will first search all the mountains around for houses like that. Why? Lets take two people - one have big house in the middle of farming spot, 10x10. 5 floors. Other have this type of base. But! Both of them farming equal amount of resourses. But with the first guy i need to spend 300+ c4 on blowing all the rooms, and still can have no luck in finding resourse room, and with this hidden base - i know for sure that they keeping resourses in one of that few rooms, so i rather hit someone who is hard to find, but easy to blow.
You shouldn't stay in places like this for long time. You have like one or two days to gather the resources needed and build a real tough base. I prefer to find/trade metal parts and build a house with ramps stacked on sides. Safest one, others can be blown with small amount of c4.