This is a topic I'm always torn on. When I started my band the Strychnines in the late 80s, we did almost all originals with the occasional cover. I wrote at least 3 or 4 albums worth of material but I had trouble getting passed my first 20 or so songs because I didn't want to let them go until I got a release out of them (which never happened) and it didn't matter to the rest of the group cuz they never cared to learn new songs anyway. So we played the same 15-20 songs for 8 years until we got bored of them. I didn't want to waste my time playing the next set of songs I wrote seeing the same thing happen (no record) so I just started dipping into Nuggets and Pebbles and having the band play those. And we learned a lot of Sonics songs. It was just more fun and less discouraging. We never toured anyway so it really didn't matter.
One thing I find discouraging though, John, is that you played on one of the few original Fuzztones albums and you ripped on those because they lacked originality. I think In Heat was a great record considering that the previous version of the band mostly did covers and saved their originals for 7 inches. I wrote songs pretty much the same way. I agree with you that he should have given his band more credit instead of claiming all ideas as his own but for being in that same songwriting school as Lux and Ivy, Billy Childish, and Paula Pierce, I think you guys did a really great job.
But you're right, those bands who claim they love the Mummies really should have taken a harder look at that band and saw what really made them special instead of relying on image and gimmicks.