You clearly misunderstood the article from the ground up, because the issue is that pension funds should not be owning stock at all (or at most very little).

Pensions should be very low risk, which is why historically pension funds invested in not just bonds, but blue chip (lowest default risk) bonds.

Investing large portions of a pension fund in stock is financial malfeasance, and if there’s a serious and prolonged bear market, a lot of people’s pensions are going to get savaged.