What happens? Really? Raiders can destroy towers and walls with their arrows. WTF.

I agree. The guard towers and stone walls should be more resistant. As for wooden walls, well, let's just say raiders can cut off the ropes which connect the wood. So far, raiders have not breached my gates, all of this being on normal difficulty.

The only good thing is most of the resources are reclaimed.

They are reclaimed, but it causes an issue as this game tends to have too many jobs in queue and can hinder progress... also, even if that wasn't a problem it just feels raw to see a guy javelening a stone wall or huge tower in mere seconds to obliteration. What is the point of making defenses? In real life, town defenses where expensive but really effective, not like here where they are cheap (up to when you build a dozen towers, where straw will become rarer than mined gold from a different galaxy), but nearly useless.

In real life, the kind of small raiding groups we see in DoM would take one look at a fortified town (even if it were just palisades and wooden towers) and nope right out.

I can sort of understand why the devs did this even if it's an inelegant solution. The game wouldn't really work well with large-scale combat (100+ attackers), nor do they have the resources to develop an AI that can prosecute a proper siege, the only way they can actually give you serious fights is by making the defenses weak enough that small raiding groups can penetrate them.

Walls may as well be tissue paper. They are not worth the building, maintainance, and reallocation of human resources. You can do ok defending without walls on normal difficulty.

V 1.1.2

I successfully used approach of building just gates and 4 towers per gate for several games. When you sound alarm horn, people run home and equip weapons and go to the gate where enemies are expected to strike. And not only people, but also dogs, which is important as sometimes I survive without human casualties, only few dead dogs.

There I select full group of warriors with "i" and when the first attacker goes for tower, I send whole group at him.

Towers function as a distraction / temporary damage soak. Usually there are some casualties on my side, but less than there would be without towers. And towers are easily rebuilt, while it takes time to obtain more people.