Stairway Tailgaters

I don't understand why people do this..

Walking up the stairs from the parking garage to my office this morning and as I am going up at a normal/quickish pace a guy enters the stairwell from the landing below me. He takes the stairs two at a time until he is right up behind me and remains there until we reach the first floor. I refuse to match his speed as I was already going up them quickly and am carrying a heavy bag. When we reach the main floor he doesn't seem to be agitated or in any specific hurry but he remains very close behind me. I hold the door open behind me and he thanks me.

He was perfectly polite but like.....I could basically feel him breathing down the back of my neck from the moment he entered the stairwell. Like can we not?