You really missed the point.
It doesn’t matter if ‘kids believe that the hard work of others should be free’ or not. Blizzard’s own rules regarding addons demands that it be free. Their rules are clear. You cannot charge for an addon, you cannot charge for a service related to an addon.
What the creator of MDT has done is create a service related to his addon which he is charging money for. What he’s doing flies in the face of the addon policy and Blizzard gets very serious about folks that break that policy.