Customers decide whether or not to go on a ride way in advance of getting close to it. They can be clear on the other end of the park. In any case, this decision is usually made far away from the ride so must be based on the ride's ratings and any rep it's gotten by word of mouth or promotions. Anyway, you see them make this decision in their status window. Once they make this decision, they start walking towards the queue entrance. It's only when they get to the ticket gate that they compare the ticket price to what they're willing to pay, and they compare the length of the queue to how long they're willing to wait. If either exceeds their tolerance, they change their minds and walk away, thinking "this ride is too expensive!" or "the queue is too long". If they decide to stay, they think "this ride is a great value" or "I don't mind waiting for this ride", and get in line.
This means that through-put only impacts the decision of the fraction of customers with low queue tolerance, who had already decided to go there in the first place. And even for them, through-put only matters if it can keep the wait within their low tolerance. Which isn't likely if the ride is popular enough to have a substantial queue anyway. That queue is made up of folks who had already decided to go on that ride, and who don't mind waiting for it. Those are the only people you're ever going to sell tickets to, and then through-put matters in how many of them you can process in a given time. But it's likely that the folks who go away due to queue length wouldn't have stuck around even if they only had 1 wait on 1 train. Some folks just have unrealistic expectations. But hey, you can't please everybody.
Anyway, the bottom line is, through-put has an insignificant on sales. Everybody you're putting through the mill has already decided to be there, and you can only sell tickets to those people. Through-put has zero effect on those who don't want to go on that ride in the 1st place.