Simply, because unlike many other casino games, winning at blackjack relies less on a "I feel lucky" or "I've got a good feeling" attitude then building up a solid understanding of the basics of the game and developing a strong, reliable and logical strategy. Always remember, the objective of blackjack is to minimise your risk and maximise your win rate and thus your profit, which you will not achieve simply by holding your thumbs and wishing for the best.
