even if you're buying well within what you can/should afford, it's terrifying to lock up most of your savings when you could be one wrong move away from being canned, or company downsizes, or you want to move/change careers. If you do lose your job, you're x number of months away from having to deal with a forfeiture, losing your down payment, and ending up renting a 1br in a marginal part of town.
it makes sense that all of my prole friends rent forever, whereas those that came from upper middle to upper class all own their own homes.