Originally Posted by Tchiowa

It's more efficient to board passengers in the back first so they aren't in the way of others. Sometimes it's more efficient to board window seats before aisle seats. And, of course, the airline may board people with status early just as a perk. Lots of decisions go into the boarding order. Do all of them make sense? Maybe not. But the airline has a right to make reasonable rules and we as civilized humans have an obligation to follow all reasonable rules.