The house wants people to win money and tell their friends, and every "winning" strategy is good for them - so long as in the end the house makes money.

There's no deep strategy in Roulette, really. I play for fun, and the money I put on the table is already spent.

The anecdote was: I wouldn't have seriously believed that you could reliably manipulate the spin outcome, and as an observer, that's true. I didn't believe the dealer could either, but after seeing this dealer pull it off I definitely see the potential for manipulation. It was almost like she was showing off that she could. And besides, she earned a hefty tip.

The house wants to make money overall. They know that individuals who make money tend to tell more friends than those who lose money - free advertising - so they want some people to make money. The total needs to be the average person loses money, but they need some individuals to make money.

On the small stakes systems they may even like it when they lose money like that - the dealer makes a big tip, and it encourages people (or their friends) to move to a higher stakes bet where they will lose more. They have to be careful about the law (which probably doesn't allow that manipulation if possible, even if it isn't in their favor), but again individuals with a story to tell are worth a lot more than than the money they lose on that story.

If anything it's the opposite: pit bosses actively police croupiers who are spinning too consistently, and croupiers are encouraged to vary their spin throughout their session to avoid bias.