Here's a non-conspiratorial reason: many engineers are not used to the uncertainty involved in day to day business negotiations and sales, and allow themselves to be stressed out what they see how the sausage is made. The reality is that lots of deals fall through, and
that is normal. But if someone hasn't had a front row seat to that, they start wondering "are we failing?", "am I not doing a good enough job?", "is our product a failure?" etc etc.
I say this as someone who leads a team that handles the promotion and enablement of engineers into a role where they have a lot more visibility into sales and strategy, and have learned that they really need to have someone reassure them until the point that they realize that things are working out just fine.
That being said, I'm not sure of the wisdom of inflicting that stress on employees that don't have a need to see the Backoffice negotiations. Is there anything productive they can do, other then getting stressed?