So every parametric eq plugin has a useless graphic view...
I don't think sound engineers would agree!
actually many do - and in some of the higher end plug-ins like Sonnox Oxford you can disable the EQ curve view for the reasons mentioned above.
models of the SSL, Manley and Neve EQs - no additional EQ curve is displayed.
If the spectrum of the input/output is displayed, that's a different matter, since it makes it easier to pinpoint unwanted resonances.