Whether or not somebody is heaving Herculean weight is completely beside the point here, although I will admit leg-press is the ONE station I would never ask to work-in on (nor have I ever been asked by anyone), as the removal and addition of plates is too big a pain in the ass.
If my gym had ONE bench press station, and some powerlifter with 600 lbs on the bar was monopolizing it for 30+ minutes, you're damned right I'm going to ask him to work in. I'll remove and reload his plates, but there is no way I'm going to pussy-foot around and waste half an hour of my time waiting to complete my workout.
Your initial point was that YOU, Professor X, never get asked by anyone for a work-in, which you attribute to "old school gym etiquette" (whatever the fuck that means), whereas "less serious types" - a group that you implied I belong to - have to deal with this inconvenience.
My point is that anyone with any balls will NOT give you preferential treatment in the gym based on your size and strength, and that in a public gym setting, you share the equipment, no matter who you are.
Do you even use the power-rack or bench press stations? The reason why nobody asks you to work in may be right there...