I might challenge that assumption (but I often question "conventional wisdom").20 years from now, the lgs in small towns will be gone...
A more accurate description may be bad LGS's in small towns may be gone, but those that know the business, their customers, and enjoy customers just hanging out even when not buying (that particular day) may well outlast some of the big box stores.
Fer example - I've been in Dunham's, Gander Mountain, and a few more and I 'bout choke on the prices - somebody's gotta pay for all that floor space, and we know who that is.
We're fortunate in our town to have not only one, but two small shops with employees with a wealth of experience and knowledge. One caters more to hunters and fisherman (with an employee / enthusiast in each discipline) and another that specializes more in SD and Class III items.
I can't really see any big box store running either of them out of business.