Don't even think he has bad aim. It's just he can't compete with zoomers with better reaction time.
I think his aim isn't even the issue, you can see at times it's decent. I think if any player had to call and micromanage the amount boaster has to, they would sacrifice their aim. Sure maybe not to the extent that Boaster does, but I think that's simply because of the 4 insanely talented players that he has to micromanage.
Think, players like alfa and hiro play disciplined when we see them on the minimap, but who would be asking them to constantly chill? alongside being a top tier IGL, also when people are not shooting he needs to be the one to keep the mood up, again while still IGLing