There is nothing called luck in "Gambling". (…) Maybe, Lotteries and contests have some luck, but they have the same basis, you win from others' losses.
What do you think decides whether a player wins or loses in a game of chance if not luck? Sure, the house generally has an edge over players in casino games, but for the individual player variance (ergo luck) is much more significant.
They simply bait people to play, make them win at first, so that they can continue gambling, but they won't leave you (or let you leave) before they extort a chunk of money out of you, this how it works plain and simple (you think that casinos don't have some people of their own staff gambling and winning a lot to attract people into gambling? think again!).
Any online casinos worth playing at are provably fair, which means that it is impossible for the house to "make them win at first" without players noticing.
How exactly does an online casino force you to play or "extort (…) money out of you"? Casinos offer a service that turns money into entertainment. Reputable ones are forthcoming with their house edge as well, so I don't understand your bitterness.