When I was in the construction business, I always felt the building owners were slow on payment, beat us up too much over the price, were ingrates for how hard we worked, the competition were paying people off to get the work we should have gotten, the union tradesmen were getting paid too much, and I just hated it when I left money on the table when we were low bidder.
After the business, I went to work as an owner's rep. I use to get a laugh after negotiations for change orders for extra work. The contractors complained we beat them up and they didn't make any money on the work. What they were really saying was they didn't make as much profit as they were hoping to get.
I guess it depends what side of the deal you're on.