But then they're already inside the house, so to speak. Your neighbors are unlikely to be cabled into your LAN.

True, but if their goal is to kick you offline then sending interference on the coaxial lines might disrupt certain cable providers.

Not in the same way that wifi is, where anyone outside the building can attack it. And even if your ethernet is under attack you have the advantage of being able to physically locate ports.

What's your thoughts on EMP attacks?

Lead vest should be worn around groin. Safety first.