Millenials also have a lot of priorities that come before investing for their future. Student loans are choking the generation's ability to have spare cash for savings and investing. In fact, I'd say the only group of millenials that are thinking of "investing" at all are the rich ones. The young middle class doesn't have enough money burn to participate in the stock market anymore.

Then there's the other problem: the millenials are living through the worst economic depression since the Great Depression. They saw the economy collapse and take out their parents 401ks which they had build for decades overnight. It's no mystery why they aren't interested in playing the sucker's game with the precious little money they have.

Then there's the third problem: we're due for another crash. It's been 7 years or so since the last one, and that duration of time is very typical from the market's peak to peak and trough to trough. Nothing has been fixed. Smart people have smelled this coming for over a year. It's a horrendously bad time to invest.