> Worse, they fiddle with them and change them before they package them up, so what you get may not be what the developers wrote. Just look at the mess that was caused when some Debian developer screwed around with OpenSSH. Or how Red Hat hosed up Perl's performance and didn't fix the issues for years.
That's like saying upstream doesn't make mistakes and all bugs are introduced by distributors. Just think of all the security holes distributors patch before any upstream developer even takes notice of them.
Also, I wouldn't trust upstream developers to package software correctly for the distribution I use unless all distributions are the same - in which case there wouldn't be any. And just look at the state of software packaging on Windows. Same base for all, no package management that deserves the name.
Distributors only providing a base and upstream developers packaging the software themselves (which is a lot of work, btw!) would probably lead to something similar.