Yeah, because comparing addons, for which Blizzard supplies an API and restrictions is the same as memory-reading external programs. At least try to strawman correctly.
Just because thud ads better functionality to diablo 3 hud even without the cheats doesn't mean its not a cheat anymore.
You still have an advantage over others, which itself is cheating, not to mention it lets you see stuff you shouldn't even if can turn that off the fact it's possible doesn't make it any less worse.
I definitely hope they deal with thud users also, and in my opinion you cheat you're out, zero tolerance.
If you deal slow with cheaters and even don't hand out permanent bans then why should people take you seriously at all as game dev, they will just continue forever.
If I follow this logic, then Blizzard should ban every addon user in WoW, because addons give huge advantage to users.
They aren't anything alike at all.