Any big chain store drives the small independent stores into the ground. If you are so concerned about the Ma & Pa stores, don't shop at any of the big box stores such as WalMart, Target, K-Mart, Home Depot, Lowes, etc...
Growing up we had no WalMart or Target. K-Mart was our only cheapo option. Where I grew up we were all ranging from poor to working/middle class, because nobody could afford high end (i.e. Nordstroms) stuff. There were no "rich kids" to make fun of us poorer kids