There is risk in choosing tenants for sure, though it is usually the case that the retailers themselves are putting in the expense and sweat equity into renovating a space. Sometimes this is cost shared, often it isn't.

I know my retailer friends painted their store themselves.

It is in the scarce retail environment where landlords have the least amount of risk around choosing a tenant because if one fails they can easily get another. So a city adding more retail zoning would increase vacancy, increase risk to landlords and hopefully reward good retail tenants.