The median US net worth is about $121k [0]. When you're talking about having $300k available to put into stocks, and saying "Just buy the stock.", that is something entirely out of reach for the majority of people.
https://www.theatlantic.com/magazine/archive/2016/05/my-secr...
Not to mention that it would be insane for someone to pump their entire savings into the stock of an individual company.
Most homeowners do this.