I think you don't the meaning of share market investment that's why you telling that investing in share market is guessing game. But real scenario is your buying a business if you don't understand the company business then don't invest in that company. So as per me share market investment for long term is totally different from gambling.
Not everyone buying shares for long term some people just treat it like day trading and nothing special about that. The fast market and high volume is the reason people use it for day trading