Exactly! We all have different ideas as to what would make a desirable kit; there are very few, if any, subjects that have universal appeal. Those few cars that come the closest to universal appeal ('32 Fords, "57 Chevies, etc.) have all already been issued over and over and over and over, because the kit companies know that particular handful of subjects will sell... they have a proven track record of success, and the kit manufacturers will obviously try to squeeze every last penny out of those tools that they possibly can. That's just good business.
But when it comes to newly tooled kits of models that have never been produced before, it gets a little trickier. Aside from the Hudson, there probably aren't a lot of "sure fire" subjects out there that haven't already been done, just models that would appeal to a relative handful of modelers. It's hard to come up with a new release that almost everyone will be interested in. The kit manufacturers can't possibly please everyone, given the incredibly varied tastes of their customers, so I'd say let's be happy that there are new releases of never-before done subjects being released at all! It's a financial risk to do that, and the best way we can assure a steady stream of new subjects being kitted is to buy the kits that are released. There's no harm in taking part in one of these "wish list" threads, just don't hold your breath for any particular new subject, and understand that your favorite never-been-done-before subject may never be released.
And no, I don't work for any model kit manufacturer...