I agree with Clint to a large extent, but on the other hand there's no reason why someone who knows skis and snowboards couldn't know bikes also - although the biggest obstacle would be finding someone who knows both. Someone in town wouldn't need to do everything that a full service shop would do down the hill - they could get away without having to know how to build wheels, for example - but they would need to do most everything else, though.
In the past I would do all my own work, although nowadays with a family and busy work schedule, I tend to send repairs that will take me more time to do myself (such as truing wheels) to a local (OC) shop. I do keep a "second string" set of tools and spare tubes/tires at my cabin in order to avoid a trip down the hill.
When I've gone self-supported bicycle touring, I've always appreciated when there's a bike shop in a small town, even if it's some guy working out of his garage. Usually it was the chance to borrow a "real" tool, rather than having to use a smaller version of the same tool that I'd carry with me. The downside is that those folks can't really keep up with all the latest technology - not that the technology makes huge leaps and bounds, but there always seems to be some new development every few years that requires a new tool.
Unless there's a relatively large influx of mountain biking visitors to a town, a small town bike shop - even a part time one - is most likely going to lose money. Here, having a hardware store that stocks pumps and tubes is the best we can hope for.
