Gambling is just one use case for Smart Contracts and it's arguably the simplest one. More sophisticated DApps will (and already are) being developed. Every blockchain has scalability issues so thats not really enough justification to kybosh the idea, but I am not going to argue with the STEEM tribe about it so lets not.
I know there was once a plan to upgrade STEEM to run on EOS tech when Dan was around and that got killed off a while back with the whole executive schism but the idea of upgrading the underlying blockchain tech to support Smart Contracts is not out of the question for me. The question is, would it really be worth the effort and expense for Justin to push that?
Personally I think migrating to TRON to realise the synergetic benefits and then potentially forking out if there's a governance problem is not a bad strategy to get the underlying blockchain tech for STEEM ugraded. Maybe it's too risky and disruptive to the business models of the STEEM tribe to really consider though.