I don't see how this article proves what you claim. It says to know your customers, because in this down economy nobody is going to pay for any more than they have to.
OTOH, most of the things that you've suggested on this thread would cost A LOT of money (especially dredging).
I look at it this way: In this economy, just staying in business takes quite a bit of business savvy, especially for someone in a business as discretionary as recreational boating. Calling the marina operators that have managed to stay in business "clueless" makes you look clueless.
I'd love to have a nice marina nearby, with green space, a restaurant, chandlery, etc. I'd be willing to pay somewhat more than I'm paying now for it (but I think I may be an exception). But I would not invest my own money in such a venture, because something tells me that the local market would not support it.