> The Shanghai stock exchange is still too heavy on insider trading, [...]

What does that mean?

Insider trading is good for the function of the market: it makes sure information is reflected in prices sooner, benefiting the general public.

> Like, you could wager some money on a mahjong game, or you could blindly pick a stock and hope you can get some money by riding in the wake of a connected insider trader.

If you are a clueless retail investor, buy a low cost index fund. Why would you be picking stocks?