Just because you CAN do it doesn't mean you SHOULD. Even if you don't think of it as "gambling", you're still taking in tons of money without providing any tangible benefit to society.
If you want to make money from investing, why not do so in a socially responsible way? Invest in companies that are changing the world for the better. You might not bring home as much money, but at least you'll be able to sleep well at night.
Not really defending the parent, but believe it or not Instagram provides something that makes a lot of people happy. Winning a bunch of money on the stock market does nothing for anyone but the winner. Not really a fair comparison.
If you want to make money from investing, why not do so in a socially responsible way? Invest in companies that are changing the world for the better. You might not bring home as much money, but at least you'll be able to sleep well at night.