In my game, I with Tracer tried to take it down. It doesn't feel like a realistic proposition in the set up that they had with Voskaya. First it's in the little enclosure with the healthpack, so you need to go deep into enemy lines just to see, right where the spawn is. What are the chances you don't get spotted? Then you have her turrets. The damage wasn't too bad with D.Va, but they slow you down to a crawl. So it's hard to even get at it when you do see it. I had to start firing because my time was limited, but because I wasn't as close as I'd like, I wasn't doing the damage I needed to it. But tracer, due to her low health, would be dead unless she killed the turrets first, and that's precious time you'd have to waste not destroying the thing that is fucking you over, right next to the spawn and the enemies. And the thing has 400 hp with regenerating shields. It takes a lot to take it down. I managed to take it down one time and died for my efforts. It was back up by the time I returned after respawning. I wasn't able to get it a second time because they were guarding it.
It's just an overly difficult challenge for the attacking team while the enemy has effectively an infinite supply of free shields for one ult. It doesn't seem reasonable. I mean, her teleport is limited. It's not like they get infinite free teleports until the machine is destroyed. They get six, then the teleport goes out. But the far more effective shielding lasts forever?
It doesn't feel right to me.