alt Hacker Newsstock options/rsus are a great example of some sort of cognitive bias (maybe it's the endowment effect?).
give somebody $1000 worth of shares in their company, and a lot of folks will hang on to them. but if you gave them $1000 cash to invest, they almost certainly would not choose to dump all of that money into their own company.
Tax-law also makes is sticky: StockX -> Money -> StockY means a portion of is lost as capital-gains tax on the money step. StockY might be better... but is it something that will perform better-enough to be worth the switching costs? (At this point logarithms and spreadsheets start getting involved.)
In contrast, starting with Money and then choosing between StockX or StockY is an easier choice.