These customers might include those who are elderly, disabled, or children traveling alone
This might be getting near OMNI, but ... what is "elderly"? Who decides (AA or the individual)? Is the oldest person on the plane? Is the cutoff at 60 or 70 or 80 or ... ?
As an aside, it seems that everytime an announcement is made for VBD, it is the outbound flight on a business trip or for the last flight of the day - meaning not worth it. In about 40 years of flying, I have gotten VDB twice and IDB never.