Trading is not totally luck based and if you have good skills and strategy then you can expect good profits from it whereas the income from gambling will depend only on how lucky you are on that particular day.
But one shouldn't go for day trading because on a daily basis no one can predict the prices any product and it will be similar to gambling. But if you just buy and keep it to sell when prices go up then trading is a good way to earn some money. Gambling is good only for having some entertainment but shouldn't use it to earn money. Both are for a different purpose and we should use it accordingly.
Trading bitcoin looks so good till today. The price fluctuations can give us very good profit. And as I can feel that this coin wouldn't be dead in the near future, hence continue to trade it, still considered as a good way to make money. While gambling will remain unpredictable. No one knows when the luck will come. The risk is too high at gambling. With trading, even though we make a wrong decision, we bought it and suddenly the price move down, we still have a chance to get profit if we patient enough.
Both gambling and trading are taking a risk for gaining profit. I agree that trading is much better than gambling because even you can make mistake on the first time, you can learn from that and will do better for the second time. Even it takes time you can surely gain profit just wait when the price is low to buy and sell it when the price is high. That is how trading works. In gambling you cannot predict when you can be lucky to win on the play. Sometimes you can lose lot of money first before you win. More losses that winnings.
Also, trading is not an investment! 
