Last year was a brutal one for brick-and-mortar retailers. Twenty-one major outlets filed for Chapter 11 bankruptcy protection, according to RetailDive. And the industry is on pace to hit that number again in 2018: Six retailers have filed bankruptcy through mid-April.The reasons are varied -- the rise of e-commerce, overbuilt malls, even a shift to restaurant spending -- and they've been covered well on this site and elsewhere.This article is not about why retail's declining.