Yes, we exist. It can be done. Yes, longer time frames are easier to work with.
The average losing trader would probably be better off buying a mutual fund or stuffing money in their mattress than playing poker. I hope no one will take that advice.
But, permit me to give a little pep talk to the discouraged.
Despite the lack of chat room evidence of winning traders, ask yourself: is anyone able to do this? The answer is yes. There are plenty of private equity funds, hedge funds, mutual funds, etc. that make money, and some of those don't even use the leverage available to the individual trader. So, if anyone else is able to trade profitably, and you are not disabled in some fundamental way, there is no reason why you should be able to do it. The only thing standing in your way is yourself. The successful people are not all smarter than you are, and they do not all have every single piece of inside information (though they may have some). Read, think, backtest, paper trade, trade small for a while, be brutally honest in examining your errors, and you can learn trading, too. However, there is one thing you must be nearly perfect at: money management. Get that right, and you can make a few mistakes on the trades. Conversely, all your trading can be right, and if your money management is bad, you will still make a mess of things.