let's be honest here…Winstons Ultimate is the least threatening of all the Ultimates. Unless a cliff is behind your enemies, you will only throw them around the Map. Not only that, but you will also turn into a big Ulitmate charger for the Enemy Team if you use it wrong and when a Mei is on the enemy Team, consider yourself dead.

It has it uses when the enemy needs to be on the Point/Payload or they lose and you just punch them away from the objective but other than that, it's not that good :/

I see it as a distraction ultimate

whether it's to help get past a choke point or to help people get in good position for an ult (ie McCree, Reaper and Pharah), A big angry gorilla serves as a great distraction
at least if the enemy team is none the wiser to your plans