Even if we have make a plans to buy something or achieve something, as long as it is while we are gambling, it will be hard to stick to the plans at that time we win money from gamble.
Although, it is only hard for those that are addicted to gamble and the new gamblers but if in any case they are so disciplined, then it will not be a big deal for them to stick to they plans that they have.
Don't ignore those people who earn the jackpot price on lottery since for sure those people can buy all things that they want for winning such huge amount of money. We see a lot of stories that lotto millionaires buy house and other expensive things. But for gambling on online casino games well maybe its hard to tell if there's really people making a fortune and buy house or other luxury things out of their gambling income. Maybe some didn't broadcast their winning but maybe there's only few of them doing this that's why it didn't get much noise.
I maybe agree that because of gambling we could not possibly buy things that we want but you also need to consider if the person is insane bettor since if this is really the real case then provably we can't really do that. Addicted person hard to control theirselves so expect a worst condition for them. And if we know that its reall bad to go thru this condition then we should set some plan and have good attitude so that we could follow all what we are planning to do.