I think I have the exact discussion that took place with cinderhulk's design:

Dev 1: Hey guys tanks suck in the jungle right now. How can we fix it?

Dev 2: What if we make a better cheaper sunfire that also gives you the most powerful summoner in the game and lets you jungle faster and gives you gold?

Dev 3: What if we made gromp buff scale on your HP so you can make it do 300 damage late game?

Dev 1: I dunno Ricky and Jimmy, it seems like these two ideas lack... something.

Dev 2: I know, it's that they don't have synergy! Lets make it so the better cheaper sunfire that also gives you the most powerful summoner in the game and lets you jungle faster also gives you disgusting amounts of HP so the gromp buff change will have synergy!

Dev 3: I knew you were a genius!

Dev 1: But uhm... what if we make tank jungles viable because of their own strengths and merits instead of just making them outrageously overpowered?

Dev 2: Are you new here? This is Riot games, we only know how to make things outrageously overpowered to make them viable! Remember our motto:

Dev 3: "Shift the meta by making things outrageously overpowered", and then tell all the players how we don't enforce the meta.

Dev 2: Right, and then laugh about it behind everyones' backs.

Dev 1: Is that really our motto?

Dev 2: Don't you remember season 3 supports? And season 4 ADCs? And why do you think everyone is playing mages top right now?

Dev 1: Because mage players are good?

Dev 3: Fuck no, we let 30 AP in items upgrade in to an 80 AP morellonomicon to hard counter Mundo! Mundo was countering double mage comps, so we let double mage comps counter Mundo and "totally didn't enforce the meta." And when that wasn't enough replaced DFG with an item that's like twice as powerful! You really have to get with the message here.

Dev 1: But people are now playing smite top lane tanks.

Dev 2: Oh ... uh... uh....

Dev 3: But our two enforced metas are countering each other out... how can this be?!

Dev 2: GET MORELLO!