Hardware has changed, some vanilla systems are still in use so you'd have to update what used it to work with the new version. And where would the developers even come from? They're not going to pull devs off of live when content already comes out at a glacial pace.
Well... Has anyone told him that this is exactly what Nostalrius staff did without asking for money? And also, I quote the text from the petition : "
We don’t have the pretention to come up with a complete solution regarding legacy servers that you and your company didn't already think about, but we'd be glad and honored to share it with you if you're interested, still on a volunteer basis.".
Anyway, I do think that most people playing on retail are either unaware of this petition or just don't care. Few of them are stupid enough to spend time to gather absurd arguments to defend Blizzard.