Approximately 31% of households do not have a mortgage. So the 50+ million households with mortgages have far less equity than 44.7%. Also, when prices were increasing dramatically in recent years, the percent homeowner equity was declining because homeowners were extracting equity from their homes. Now, with prices falling, the percent homeowner equity is dropping dramatically.
If it becomes socially acceptable to walk away from a mortgage, this will be a structural change and will cause a major change to the mortgage landscape and additional pain during the transition.