The margin for what is considered reasonable makes this hard.

For example, ten briefcase holding passengers, ready to leave the plain, would probably urge someone to make room when they start to reach for the first bag of a total of seven while blocking the way.

Some people will not want to hold up a line when they judge their actions will hold up the line for a long time. But at some point you have to get up, you cannot stay in the plane and not everyone can be last :D.

But it must be frustrating if you are ready to walk out the plane, that fellow passengers decide it is reasonable to start blocking your way.