Certainly a lot would depend on the property. Is it marked "Private Property"? "Employees Only"?
I've turned around in business parking lots, or perhaps briefly stopped for one reason or another. Generally retail parking.
On my bike, there are a couple of parking lots that I'll cut through.
- One, 4 lane? road, no shoulders, planning a right turn 1 block ahead, long parking lot, just makes it easier.
- Turning onto a 4 lane, semi-divided road. Needing to make a left turn about 1 block ahead, sometimes it just makes sense to cut off and stay left rather than crossing all 4 lanes too get to the bike path, then making my way back to the left side to turn a block later.
As you mentioned, road construction places unique demands on traffic flow. And, apparently some people see your business roads (with stop signs) as an extension of the road system.
I can't think of many large private campuses around here, but I might consider cutting through a shopping mall lot if I thought traffic moved better that way (except shopping center lots often move slowly).