Software engineers have full-time managers (which are a lot more overhead to pay for but kinda serve that purpose from the client perspective) and are paid well enough and consistently enough to usually only work one job on a given day. Subcontractors sometimes do decide not to show up to your job site because another employer offered them a bonus to do theirs that day instead. The point isn't (only) to humiliate or do a show of power to the workers, it's to counter an economic incentive they have.

That said, for a lot of subcontractor trades, it's so hard to find anyone that I'd worry about the reverse: you get known as "the freaks with the cameras" and no one good bids on your stuff anymore, and then the delivery is even more delayed.