Good horse players do not gamble good money only on a horse's "chance to win." There is another important factor that is ignored at the gambler's peril - "the expected payoff."
If the expected payoff exceeds the the horses chance to win, it is worth a bet. This is comparabe to an investors assessing a Risk / Reward ratio before investing. (You do that, don't you?) If one evaluates things that way, you can say that "Every horse in every race is worth a bet - if the payoff will be great enough; and every marketable stock is worth buying if the price is low enough."
In the stock market, I can see the possible rewards out there, but I am waiting for lower prices to reduce my risk before committing hard earned money.
Lot of similarities to the track...
First, all of the players are "experts", whether they pick the nag or someone else does.
Second, No one ever admits to losing, everyone always wins or comes out even.
Third, the money players control the race from the gate to the finish line.
Fourth, it is always the little guy that goes home shirtless, sooner or later.