I mostly started doing this because I noticed that at least when on sale, Jordans/Air shoes seem to be both economical and of elevated durability and quality compared to traditional running shoes. I also like high-tops and find the comfort and support that they give my ankle to be nice.
That said, I do live in Nike's back yard and that may have something to do with the seeming obsession I've seen among men for sneakers.
re: all the other people claiming it's entirely "status" - where is the status of shoes who normally retail for ~100-150$ USD when not on sale? That's like two levels above bottom of the barrel. I claim there are other reasons for the success and admiration of those shoes.