Yes, there is ways around a hardware ban. The thing is, most cheaters aren't rich enough to replace components, and/or aren't smart enough to change the MAC address. So a hardware ban eliminates a lot of cheaters.
Plus, it is oh-so-very easy to issue a ban, but a pain to un-ban yourself. So you get banned in a split second, then spend possibly hours to un-ban yourself, only to get banned again in that split second.
Plus, it is oh-so-very easy to issue a ban, but a pain to un-ban yourself. So you get banned in a split second, then spend possibly hours to un-ban yourself, only to get banned again in that split second.