If something really crazy like progressive capital gain tax is introduced then a lot of people will rather consume instead of taking bets with a lot of risk attached to it and very little upside. This goes for every high tax: if the upside becomes not very tempting you may just as well settle on what you have and stop trying to improve your situation/produce more as huge part of that surplus will be taken away from you anyway.
You are more willing to invest at 1:1 odds than you are 100:1. Especially since the odds actually don’t reflect the actual risk of the investment itself. 100:1 on a sure thing is better than 1:1 on something that is very high risk. However, no investment is a sure thing. There is a non-zero level of risk in any investment, so if the payoff doesn’t match the risk, you simply will put the money under your mattress.