You're saying foolish because you don't know what you're talking about. It's the standard know-nothing dumb childish smartass thing to say. Thousands of people earn their living doing it, earning more than you can imagine. Most don't publish it on a DIY website.
Even Noddy Holder's roadie should be able to understand this:
You buy when it goes blue and you sell when it goes red. The candles' width is time. You can't tell without looking at the scale whether it's weeks or minutes, you get much the same all the time. This is "trending up" which helps, but it's not necessary. The blue bits always go up.
It's not like gambling, because you only put your money down when it's winning - it has already turned blue. Sell when it turns red. Of course the next one can be different, but look, it doesn't happen very often so it doesn't matter overall. Now do you understand?
You can of course also "short" the bits that go down. You would be winning if you only did that and ignored all the risers. I suppose that blows your mind. Many simple strategies like that work, though they can be improved. At finer timescales you can tell when it's losing momentum and is about to turn - like when the candles get shorter. Look at the first few blue candles (include the wicks). The 3rd and 4th are longer than the 5th and 6th
Put and call (sell and buy) options aren't complex to begin with either. They're a useful insurance.
Forex derivatives are p easy too, as is spread betting. You can get into trouble selling options, but I won't bother to explain it because you wouldn't understand. The only one which is classed as gambling is spread-betting, which is surprisingly simple. WInnings are tax free so it's popular.
FOrex is simple too. If you pick a calm one like USD/AUD the price drifts overnight. You see which way it's drifting. Let's say up. So you buy, and put a trailing stop loss which sells it if the price drops more than some small amount you set, below the highest it's got to so far. So you might start off winning say a dollar in 5 minutes.
After about 5 minutes the "spread" is covered so you're in profit. If the price drops say a dollar, it sells automatically. Sometimes it'll run for 20 minutes, sometimes all night, it depends if it wiggles. So you wake up and have a look to see how long it went for. Trouble is, if you go to the loo in the night it's too tempting to have a look and see if you have to set it going again. Last time I did it I gained $7. Previous one was $87.