Gotcha, So they spend money on baked goods and bike supplies. But they are not going to stop along this Folsom to Lake Tahoe trail at the local hardware store and buy that new lawn mower and attach it to their bike for the ride home. Or maybe stop off at some antique store along the trail and purchase a chair or a desk. Where on their bike are they going to put that new tv or computer they purchased to help out these local economies. You and I both know that they are out there to get a workout and ride the trail. Not to do their weekend grocery shopping and running errands for big ticket items.
The little sundries or croissant they buy at the beginning or end of their ride might be helping the one or two stores that have a big enough parking lot to let these people store their cars for a few hours while they ride, but I surely don't think this it the "boom" to the economy that is to be expected.
I would ignore this, but you hit a nerve. This is always the argument people make about bicycling being only good for recreation. It's patently false. Let's start with the antique store. While I might not bring home the dresser on my bike, I also might never get to that antique store if it weren't for the bike ride. Now that I've ridden there, I might drive back to purchase that too-big-to-carry item. If it wasn't for the bike ride, I would never have known that store existed. I've done it before.
Second, like hardware stores, antique stores sell lots of things that you can carry on a bike. I routinely ride my bike to the hardware store for random hardware, light bulbs, tools (power and otherwise), batteries, etc. Last I checked, people buy those things much more often than they do lawnmowers, yards of dirt, 4x8 sheets of plywood, etc. The last time I bought a lawnmower was almost 20 years ago. And, of course, you can get all those big things delivered if you want. Oh, and, yes, I have carried a wall mirror and a toaster oven on a bike, and a sink (bathroom, not the kitchen one) in a bike trailer. So I don't want to hear about bicyclists not spending money at non-restaurants. And, by the way, in those cute little towns, most of the money is spent at restaurants anyway.
And you're missing the point about the restaurants. The restaurants in the HD are a destination for bicyclists. Sure, some use it as a staging area and don't spend any money, but just as many ride from further down the bike trail, have lunch in Folsom and ride back. Those are people who would not be eating in Folsom if it were not for the bike trail. And along the way, they discover the rest of the offerings, and are more likely to come back.
Then, of course, there are events such as cyclebration, which draw from thrughout northern CA and result in hotel stays, and more restaurant income.