Quitting their job to be a full time trader is risky. Sure some people made it in the past and had success, but it's not a consistent source of money
Yes, if they don't have any skills in trading, of course, that will be too risky because they cannot expect and hope to always make a profit, especially at this moment. Right now, the market is not stable, and the price can move to any price, so if they cannot analyze with the right, I don't think they can be able to make a profit.
But if they learn more about trading before and they think that they can make a profit in any situations, then quitting from their job could be possible because, in the trading, we have a chance to make an unlimited income that will bigger than our jobs.