base cost of a coin should help miners to determine whether they are going to mine or not mine.... including help them to decide the extent to which they will expand or shrink operations or attempt to make their operations more efficient in order to attempt to be profitable.
While this is basically true, it's worth noting that mining expansion has typically been limited by equipment availability (once thing got past the initial "anyone interested in this thing?" phase). This has lead to mining not quite following price which may partly explain the misapprehension of price following hash.