Private, Group, Clan, organized legit dueling still exist and are very active.
You don't have to compete with people who use hacked items (I don't call them hackers.) Compete with hacked items with legit
is pointless, there is a reason for them to cheat.
It is not as easy as you think to get rid of Iths, but I agree that Blizzard has spent little time on Diablo2 since 1.09.
Your theory is basically, can't beat it, cheat it. Just because many people cheat don't mean you have to, but I won't have a problem with that, since it is your choice afterall.
We don't know what Blizzard will do with Ith in 1.10. Possibly making the new legit items more powerful thus making the Iths worthless
Anyway, there are a lot of legit dueling groups out there, and there is a reason for being legit and not cheat.