Why does it matter who is to blame? Who is "responsible"?
To me, this just seems like purposefully looking for ways for one player to feel superiority over another for an issue within the game. "I didn't cause the problems! It was X's fault! Blame them!"
If there's a problem within the game, rather than wasting time assigning blame everyone should just be working out how to solve or mitigate it. To me, it's no different than people who throw around "RAW" as a defense against fixing issues. "I know you are having problems, but I'm just using what WotC wrote in the books. It's not my fault, it's theirs! Until WotC changes the rules, there's nothing I can do to help you."
It's all a waste of energy in my opinion. Just fix it. It's not a big deal.