Actually, a lot of roguelikes do have towns or stores. The original rogue did not, but it initially split to into four major branches: moria, omega, larn, and hack/nethack. All of those have towns or stores to sell and buy items. Then the dozens of variants which also carried over the stores. In fact, outside of rogue, i cannot think of any that do not have a town or store to sell items. I think you mentioned crawl, which I admittedly have not spent much time with.