Just look at a roulette wheel... the casino takes that 5.26 percent and really doesn't care if Red or Black wins. They want the action. Or in craps... you've all seen lazy dealers pay with "dirty money" wherein they take someone's losing bet and use it to pay off some player's winning bet without first having brought the chips back to the dealer's work area to be "cleansed".
Ofcourse the dealers can be rooting for the players and hoping for tips. Red, Black; Odd, Even; Pass, Don'tPass... it makes little difference to the casino. Thats why the casinos are perfectly willing to comp you if you win, even if you win big! When you lose, they take your money. When you win, they take a little bit of your money. If you walk out those doors a loser, they have your money. If you walk out those doors a winner, they know you'll be back in town and most likely you will back in their casino.
There is a pretty common misperception that casinos want all the players in the casino to lose all their money. This just isn't true. If people didn't win at least a reasonable number of times then nobody would ever come back. It's slightly different on table games depending on the casino because one whale can affect your monthly or quarterly win. We've all heard the Kerry Packer stories. On slots most casino personnel will actually be rooting for their regular or friendly customers to win. All the casino does is take money from one customer and gives it to another customer and keeps a percentage in between.
Casinos would be much better off if players did lose all of their money and just kept coming back for more. The fact is that a casino, on average keeps between 0 and 15% of each dollar spent depending on the game played and the skill of the player. From that edge, they pay all of the casino expenses and personnel and keep the rest for profit. Generally, (from my experience seeing the books) table games do not contribute much to the casino's bottom line at all; it is the slot revenue where 90% of the margin is made. There is always pressure to add more slots and take away table games especially when times are rough.
Casino personnel are rooting for players because they know that winners tip more than losers. Personnel who do not earn tips are rooting for the casinos. Casino personnel also know that better experiences at a casino bring them back. It's a fine balance though because when a casino loses money, the formula is broken and that usually results in cutbacks.