Indeed, this.
When you have more people wanting to ride it than it can handle, then there will be people who can't ride it. And no matter what system you use to determine who those losers will be, they will think the system unfair.
There is no perfectly fair way to handle this. Only systems that favor one group over another based on reasons for favoring those groups. The groups that get left out will argue that your priorities are wrong. And thus... no perfectly fair system that everyone will be happy with.
And, as
@DarkMetroid567 mentioned, the system in place is to favor Operations. They schedule a known amount of guests that they presume they can handle, and if they can't, they get comped. Then they schedule a known amount of guests that they may not get to and call them "backup". If they don't get to them or only a part of them, they don't have to comp them because they're "backup."
They use a virtual electronic lottery system by having everyone slam a server all at the same time. Again, this is for Ops, because at DHS, people were showing up earlier and earlier to win the lottery, and they had to stop that before they wound up opening at 3 AM.