It's a beta. Part of testing a game is finding bugs and informing the company... A bugs section on the forum is a great place to do that, if more people abuse it, they'll just get banned if the Devs use some backbone on this.
There are quests that you can only complete once im pretty sure. Not that that is even a big fix to make a quest non-repeatable. lol, you act like its some major game change
It is the method, its also for sale on many different sites. I saw it on Epicnpc.com, D2jsp.com, Reddit has a thread with it and if you enter the zone of the quest its constant spam of people asking for groups for the "Share" of it and for "boosting" or just asking for people to Trade leveling. Its pretty bad.