I assume you're referring to the Calf plugins then. Well, I can't use logic against feelings. All I can say is that the the utility of such displays is as questionable as their accuracy is suspect
I've actually wondered about the accuracy of the calf analyzer because its behavior seems a little strange, but the spectrum is useful as it is and better than *ahem* nothing. The calf compressor graph is accurate enough for me (it'd be even better if it provided a fabfilter
-or-ableton-type graph). The calf EQ (and also eq10q, disappointingly) doesn't have a builtin analyzer that you can look to EQ off, but the way the knobs and buttons are organized is much more intuitive than most host-generated UIs I've seen (especially eq10q), and having the EQ laid out visually like that is helpful even without a builtin analyzer.
Also, if you mean to suggest that such graphical feedback is actually irrelevant and you "only need audio to edit audio", I disagree with you. For example, do you only need your eyes to accurately color correct video footage and stills? (The answer is no. Many editors use vectorgraphs
that detail color information in the frame. Without that visual feedback it would take much longer to color correct as accurately as with it.) Try to find one relevant OS X/Windows DAW with a builtin EQ/compressor that does not offer some sort of visual information or frequency spectrum. The reason for that is not "because they want to smear their branding on everything", it's because visual feedback can be incredibly helpful and often time-saving. Here
's a video demonstrating a very common scenario that would be much more difficult without being able to see a frequency spectrum.
I'd just like to note that there's no reason that a host couldn't provide such an interface for a ladspa plugin automatically if given the appropriate hints--without suffering from the integration and usability issues that plugin-provided GUIs entail.
I've seen people discussing this idea and I am entirely receptive to that possibility. But as far as I am aware it is still only talk; there are no hosts that currently do that and furthermore no plugins that try to. In the meanwhile, instead of waiting 3 years for that to happen and using feedback-deprived LADSPA plugins until then, I prefer the current LV2 offerings, even if they are lacking.