I don't know why people say bitcoin is gambling. Its not gambling. You are investing your money and time. You use your internet. So its not gambling dealing with it.
how we get bitcoin and used for what .. for buying and selling i do not think gambling .. gambling can not we specify the profit, but for sale and buy we can determine our profit .. example we buy bitcoin with price 10k and we will sell it with price 15k then we already know we will profit 5k.