The idea of traditional zoning is to segregate land uses. For example, zoning should protect the value of ownership of retail or residential real estate from the effects of a tannery locating next door. In a sense, zoning is a mechanism for separating land uses that could be considered nuisances to neighbors.
But in practice, zoning can have the effect of regulating economic activity that has nothing to do with land use. A zoning dispute over a consumer loan office illustrates how zoning applications provide an opportunity to allow the public and the zoning board to get into such non-land-use issues as the size of a loan, the time allowed for repayment, or whether the collateral for the loan is a car or a post-dated check or something else.