A not so epic stair-down

I’ve been working in an office building for a couple of months now. I’m on the top floor of an 8-floor building in the city (quite the skyscraper I know). The mail center in this particular building is on the 6th floor, and there’s another company that has offices on the 7th and 8th floors. Why am I giving you a detailed layout? Because I’ve noticed something about the other company that tends to bother me: they avoid the staircase like the plague. I admit that I have just as many (sometimes more) bouts of laziness than a lot of people, but when dropping off mail, I take the stairs. Why? It’s mainly because of the pseudo exercise I tell myself that I’m getting, but it also has to do with this growing epidemic. I can’t tell you how many times I’ve taken the elevator to the ground floor and had someone take the elevator from the 8th to 7th floor and then another person take it from the 7th to the 6th floor. The staircase leads to the same place as the elevators do, and it’s 2 flights of about 10 steps each! Once, I overheard one of their employees say he was going to the mail center, so I took the stairs at a regular pace and beat him by a suprising margin. I’ve been trying to figure it out since I started, and so far I have nothing. Every person I’ve seen on the elevator could physically handle the stairs without any difficulty. Is it possible that an entire company is vehemently against taking the stairs? Is it perhaps company policy? Either way I don’t get it. But if you’re taking the elevator less than two floors, then I suggest doing it alone.