[zzzeek]

They care because trampolines have a very high rate of injury. If you throw a birthday party at your house and one of your neighbors kids breaks their arm or worse, neighbor might decide to sue you. That then puts your insurance company on the hook. Even if your policy forbids trampolines you can often plausibly argue you weren't aware, and they end up having to pay out. Insurance companies refuse to cover things all the time and trampolines are apparently a big problem for them (just talked to our insurance broker a few weeks ago about this as my family is pushing to get one and I'm having to push back.)