For starters- Asshats always will exist. No method, even hardware banning, is fool proof. I have several motherboards laying around myself, & various processors & video cards too. Parts are cheap!
2nd: People like to power-trip. This is an excellent way to kill your sim. A Hardware Ban for Private sims is good tho. You pay to rent that spot for your lil' idea of paradise, you should have some control over it.
3rd: I've been here a year (almost), got a chunk of land, a shop. I have yet to see anyone there causing problems. Or maybe I'm just a nice guy? I dunno, but some of this "griefing" seems to only occur to some people.
4th: The addition of a database for every land and sim owner to keep data on who's banned is more crap to keep on the asset servers. Do we really need them to do more?