Because management should be rigorously defending devs from being needlessly interrupted with whatever some sales guy thinks is important in the moment? Management can filter out the garbage, condense down the really important bits and deliver them during a time it won't knock dev out of the zone?

Worked fine where I worked. You know you can turn notifications off? You know you can tell a sales guy he's being annoying?

We were banned by management from turning off notifications.

I once worked at a (open) office where sales people were constantly berating engineers, asking for a feature or pestering for a status update on a feature/bug in progress. It got so bad they installed a wall around that area.