I'm surprised as a dealer, he hasn't been able to see that.
In today's auto market, there are so many different offerings from so many companies, as suv_guy said, the market is fragmented.
Back in Explorer's heyday, there weren't too many options to choose from, and Explorer was the best of those options, thus, producing the sales it did. With all sorts of options now, not everybody is going to flock to one product, unless there's a very good reason to. It seems that each option today has it's own good things, which makes the decision even tougher for a customer.