No, you're not the only one. But, at the same time, it isn't always the absolute top priority. Right now I'm working on a couple of systems that have had a few mystery DLLs in them. Not necessarily anything lacking source code - it's around "somewhere" - but certainly things we've lacked the immediate capability to rebuild.

But those DLLs aren't the only, or the biggest, problems with the systems. Hence finding the source and building them from it isn't necessarily the top priority, although we are progressively doing exactly this.