What specifically should "disability" mean when it comes to qualifying for SSDI? That is the important question.
If disability claims spike during a recession, if there are unusually higher percentages of people on SSDI in economically depressed communities, and so forth, that is a bad sign, because it probably means people are turning to SSDI because they can't secure a job. That is not what disability is. If it was, then a lot of 22-year old college graduates would be "disabled."