Oh! I thought that you were "returning" after just a few months. Well I suppose you still are, but if it's only once per account it's a real drag then.
If you think about how many legendary minions you get in a starter deck compared to just completing your quests, it's really not that much you get to compensate for the months that you had to be inactive. Sure, playing should be rewarded, but I don't think that people who love playing for hours every day should feel tricked if their friends also get to play with a good deck every now and then.
I suggest some quests that can earn you some mixed packs after not exceeding a certain play time, over a long period. Maybe even give the BGs-only players some incentive to come back to standard?