My wife and I are both retired from United with a total of 60 years service. Even for us, pass riding is a nightmare, and has gotten worse with the Continental merger. We’re on the bottom of the list. Continental is the surviving carrier (they just like the United name better).
Also, my strong impression is that back in the day planes flew with empty seats all the time, but as airlines continue to cut costs and improved profitability it is considerably more difficult to fly standby than it was even in the 90’s.
Not that that’s bad. The function of the airline is to make money getting PAYING customers to where they want to go. Empty seats is bad business.