There aren't enough of these stores to impact any major metro area. Aldi tends to have more storefronts and their impact hasn't been that great. What did smack the old school grocers was when Wal Mart got into the business years ago and to a point Target.

example, there less than ten Whole Foods stores in Metropolitan Atlanta. There are probably that many competing grocery chains in the same area, with sixty plus of each of the larger ones.