Because it's only about the "good" time. And they pay for female company without their money, they could NEVER have, much like pimps.
So? Everyone involved is an adult. Nobody is lying to anyone or promising anything that they don't intend to deliver. Look, women are drawn to successful guys, everyone knows that. Guys with good jobs and money aren't "pimps" for using their success to attract women any more than beautiful women are whores if they use their looks to attract successful, rich men.
I'm really not sure what you find so offensive about the whole situation. If a guy buys a woman dinner, or flowers, or jewelry, does that make it prostitution if they end up in bed together?