Agree, they were only notifying when reservations became available - it was up to the individual to go to Disney's website directly and book. They were always explicit that they did not guarantee nor book reservations. No different than if you were stalking the site yourself to reserve - you were just paying someone else to be your eyes.
But it speaks to the larger issue of other sites outright selling reservations, holding reservations under fake accounts, etc. If Disney is already going after sites like Disney Dining Buddy to shut down operations, I imagine they already have or will soon be going after the others as well. And while I believe that Disney Dining Buddy was fairly benign, it's a slippery slope and I understand Disney just wanting to wipe them all out.