Current gen consoles becoming the baseline is probably it.
As games running on last gen hardware drop away, and expectations for games rise above 1080p, those Recommended specs quickly become an Absolute Minimum. Plus I think RAM prices have tumbled as well, meaning it's almost Scrooge-like not to offer 16GB on a £579 GPU.
That said, I think the pricing is still much more of an issue than the RAM. People just don't want to pay these ludicrous prices for a GPU.