Plus as others have said, usually all of the decision makers have a bunch of stock exposure and will prioritize their own financial gains over pretty much anything else.
These are often both weak signals, though. They'll govern very high level decisions, but all the day to day is inside the company. Just as I want a return on the money in my bank account (as I was promised) investors want a return on their money too, and as you say, the executives and board should care about making sure the people who put money into the company are getting a decent deal out of the arrangement.