The sad truth about raiding in this game is that if it is worth raiding, you probably can't. To me its not worth travelling more than a few minutes to get wallgrade steel, because I could just fire up our crucibles and make a huge batch, compared to the 6 steel that new players normally make. New players never have cheese worth taking, and again, its easier to just make it myself. What else is even worth taking? I guess silk, if they have it, but thats pretty rare and unlikely. Its even easier to make your own developed skulls if you do it in bulk, since often newer players wont even satisfy the conditions.
I guess that the motivation is just griefing, which I've never really understood. Either that or people are pretending that it in some way palibashing a little hermitage makes them a badass, which it doesn't, it just means you have cows and some cheese trays. Most of the people who get raided don't even fight back: killing them doesn't mean you are good at combat.
I'm hoping this will be addressed in future patches: it should be relatively easy to "raid" developed places for loot if they dont actively defend it but hard to level people's settlements. I have no inherent problem with raiding but it seems weird that people do it for so little reason and in such a cruel way.