There are people who have learnt how to trade, practiced on demo accounts for long but have not had the money to try trading on the market, and so they have abandoned trading to try search for money first. While there are others who have too little income, that they cannot profit from the market trading, they are always worried about loosing and because of that they make mistakes with their technical analysis and end up loosing the little money they have. Should trading be exclusive to financially comfortable and rich because of how risky it is?
Trading is suitable for everyone but many people don't make money from trading because they don't have enough money. People who don't have money can't always prepare for trading on a trading platform because they always fear that if they lose money then their situation will get worse from various fears that they have to gain enough experience to stay away from trading. A bit more useful in case of the rich as they have no shortage of money that they can trade with huge sums of money thereby making money from them. If you think deeply the answer comes trading is very easy for rich people because they have enough means to supply money they are never afraid of trading because they don't lack money. So while trading is for everyone, bring a little more benefit to the rich.