You’re absolutely right: 47% of households own equities. And of those households, the top decile owns 80–94% of these equities and almost 80% of non-residential real estate. The top 5% own about 70% of the market. The bottom 60% of households — those that make around 65k a year — own a meager 2.5% of shares. These figures can be found in Edward Wolff’s 2010–4 studies on the concentration of financial markets. (Wolff is a respected economist at NYU, which leans freshwater, so it’s not exactly a hotbed of Bolshevik activity). Wolff estimates that even fewer people will have the money to invest in the next decade, due to stagnant wages and the impressive collapse of discretionary income brought on by exponential increases in the cost of civil necessities.
So, I’m cool using the stock market as analogy for employee ownership if you’re cool with 60 out of your 100 employees receiving 2.5% of the benefit of the company, and 5 out of the 100 receiving 70% of that benefit.
Also saying “just invest” to people who have little to no discretionary income is the consumption-side equivalent of Romney telling 17-year-olds to “sell some stock” to pay for college. I know you don’t mean it that way, but it’s literally impossible for some people to find extra money to put into finance.