I have yet to see it proved that it does actually have anything to do with the block size and not miners deliberately postponing confirmations, for whatever reason. Whoever is going to challenge that point, you know what to do. Basically, you should provide a list of the blocks mined since about time this congestion started with their respective sizes. The list is not going to be long, there are only 144 new blocks mined daily on average, and we will easily see who is right and who is not...

Anyone willing to compile such a list?