I dunno - my in-laws bought their house in 1986 on a single engineer's salary (then renovated it into a bigger one when my mother-in-law went back to work). I also had a number of coworkers at Google who bought houses in 2009/2010 as single tech workers. Heck, I could've done so myself (2BR condos in MTV were going for $400K at the time), and am kicking myself for not doing it.

Perhaps 09-10 was a bit of an aberration because it was the middle of the foreclosure crisis and housing prices bottomed out then. I guess another big "thing" is parents (particularly Asian ones) paying the down payment for their kids - 2 of the 4 coworkers I'm thinking of had that help, and one had a minor stock-option windfall from joining a company right before Intuit bought it.