I believe it's both. First it's the cash, then it's the age.It's not a young man's game. It's a money talks game. SPs don't choose this line of work to be have leisurely sex with young guys they're attracted to (they usually do that on the side if anything). They do this to make money off the men who can afford to pay their rates. A lot of SPs are closer to being 60 than they are to the age of the young men who you think you're in competition with.
Now more than ever I see late 20s and 30 something nerds getting a lot of action from the younger providers. Think about it. Blowing some young dick, eating his arse versus some old dude? Sure, the old ladies at Swan will do it, but the taste of fresh young meat certainly has some effect on their mojo. Thankfully, if you have the bucks you can choose to see @rinamood, a genuine unicorn.