Do they need to make the rewards for ladder considerably better? I used to rank to 5 because the rewards for legendary weren't worth the time lost playing arena. Then I made the same rationalizations for dropping down to 10 and then 15 last season. And I don't think I'm wrong even at 15.
Play arena to collect cards, play ladder to...? With that realization, the long term goal just becomes collecting cards which feels kinda shallow since nothing long term affects arena.
I guess there's golden portraits.