I've purchased dozens of online products and have reviewed hundreds over the years and I can assure you that about 75% were junk.
So the answer is YES.
I agree!
This sort of thing is pretty common with IM products. The sales letter promises you the world in them, projects the product as the next big thing, but all you get inside is some rehashed content or a simple technique blown up into a 80-page pdf.
If you're looking for a copywriter for a product where the quality is not necessarily bad but just the concept, method or idea is old, I suggest you hire a copywriter who is NOT familiar with the concept/niche.
I once wrote copy for a product where the concept was old in general, but still it was new to me. I had never heard about it before. So I was able to present the product in an innovative way and the copy converted at 7%.
But if I was already familiar with the concept, I wouldn't have been able to present it in an exciting way, right?