Wow he has a nice store and a friendly kind of guy. I'm sorry he doesn't feel the other companies can carry him along.
When you're primarily an MTH outlet, as Dave is, the closing of MTH means that your business model will no longer be viable. You've been selling a certain product line to a target market that wants that product line, and then the product line ceases to exist. To continue in business would be somewhat akin to starting over. The same would be true if you were primarily a Lionel outlet and Lionel went out.
Very unfortunately, I expect there to be more closings of stores that primarily sell MTH. This is perhaps a cautionary tale to not base your business on one company's product line.
I saw Dave and his layout in an OGR Great Layouts DVD and I was super impressed with Dave's skill and artistry. I've also admired his work through his articles in OGR Magazine. I'm sure he'll be very successful in whatever he decides to do next.