If it really is a problem for you then work around it. But for most of us installing dev files makes sense if we ever need to compile something against those .h files.
Disk space may be cheap but limited. It just makes no sense whatsoever to just put a lot of files on my disk i will NEVER care about. NEVER.
And if i need them, i will install them. Usually i only want a freaking binary to run.
If it really is a problem for you then work around it. But for most of us installing dev files makes sense if we ever need to compile something against those .h files.