I have a mixed reaction where you said that some gamblers after years of no wins still push harder. There are two kinds of players in this category which is unclear which one you're referring to, and both sides also know gaming is all about luck; the responsible and compulsive gamers. However, having a detailed strategy and practicing it, helps players to be time and money conscious, and facilitates responsible gambling.
I don't believe that gamblers never win after they gamble for years. They should already win few times, there should be lucky time for the gamblers. When they become more familiar with certain gambling games, they must have a better chance to win it. Sometimes experience has a role to determine the chance to win although the luck factor has a bigger role. Well, I can agree that a strategy is crucial for certain games (blackjack, poker, sports betting). But for other games, it is not really crucial because it is basically nothing to do with a certain strategy. Luck is surely the main factor to determine the chance winning the gambling games.
If one is not consistent in gambling it is possible not to win or maybe to win only few games and sometimes when the number of loses is so huge it's just as if one has never win any game in gambling. But if it is a gambler that consistently plays gambling I don't think it is possible not to win gambling, it is possible that loses is more but there are wins that one would be able to remember. Winning gambling is based on luck but experience also plays a role in the outcome of every game, and consistency in gambling can only give one a better experience to understand how gambling works .