Class diversity is pretty hard to achieve because you usually need some baseline class to actually be able to succeed in a role, i.e. you can't show up to a meeting with customers or shareholders chewing dip and wearing camo jorts. And social mobility from lower classes into corporate-ready roles is rather low in this country, so while there certainly are people who grew up poor and would be useful for companies to figure out what lower class consumers might need, there aren't many of them; furthermore, for the people who did grow up that way and into being a person able to function in the corporate sphere, it's probably in part due to their rejection of their poor background.
Maybe we just need more focus groups.