Dude,
I understand that the average joe isn't as knowledgable as we are - and trust me when I say the WE (as in you and I) are not even that knowledgable. Everyone wants to be a pro...just like I do
With that said I still don't think it would mtter if Vince directed a PXP title or not. Your logic is skewed. Just because the customer likes what Vince Voyeur is doing with his guest stint on a PXP movie doesn't mean they'll ever buy another PXP movie. Why? Because it won't be the same movie. Vince will not be directing it. People buy based on performer, box cover, director and studio. Now that may not be an exact order, but whatever that order is, I can almost assure you that studio is not number one. I should also add genre to that list. Oh, and male talent too.
Let me ask you something: do you think revenue would go up if Francis Ford Coppala directed the next Star Trek? Do you think there would be more Trek fans as a result? Do you think Paramount Pictures would get more of the movie buying dollar? Most likely not.
One good director making one video for another label will not bolster long-term sales for that label. It takes good directors making consistant, quality product for the long term. Anabolic is a good example of this. They essentially lost all of their directors. What was the result? They're still big, however I doubt sales this year and sales for the titles releaded - sans those with known directors - will rock the sales chart. I know they'll bouce back big, but it was a hit I'm sure.
For the most part, people follow known names and brand. But the balance is moving more and more towards name everyday.
Finally, don't forget, these guys all have personal investments when it comes to doing their own line.creative and financial as well.