Yeah, in most cases productivity applications are system friendly and for the most part I don't see a need for a WHDLoad like installer for them.
But on the other hand there are some good apps that are just broken under later versions of the OS and RTG. It might be nice to have something for this. I'm thinking of VistaPro, Gold Disk PageSetter and ProDraw, etc. Those either have problems under OS3.9 or won't run if RTG is enabled (even if they are not running an RTG screenmode).
So maybe a WHDLoad installer just for the broken apps.
Actually, now that I think of it - Lightwave can be installed in an RTG system if you know what you are doing, but some sort of automatic installer might help for most people who don't want to figure it out. If the WHD Load installer could also apply patches to the applications to make them run under RTG/AHI (if patches were available) or something that would be great!