Great post.
Did a little digging on the AT benches and Wikipedia...
Look at the history before Crysis was release. For example, the 7900GT was ~2x faster than the 6800GT it replaced as the high-end single-GPU offering.
Then the 8800GTX was released at the end of 2006/beginning of 2007 which then improved EVEN more (something like2-3x performance). That means in about the 2.5 years leading-up to Crysis releasing in 2007, we saw graphics speeds increase 4-6x. Thats pretty impressive!
Then look after it was released and you see in the last ~5 years, we have seen graphics 'only' increase ~8x.
http://www.anandtech.com/bench/Product/514?vs=508
Crysis was WAY ahead of it's time, and I trully think the developers were thinking the huge gains we had seen in the 3-4 years before it's release would continue. Unfortunately, thermodynamics and 'consol-itis' got in the way and we became accustomed to much slower GPU growth. Let's assume the performance improvements of 2005-2007 continued through today; Crysis would be MUCH more playable on 'high-end' machines with mods and eye-candy maxed-out.
To say this game looks like crap is VERY naive. The fact that only 3-4 games in the last 5 years even fall in the same discussion is proof enough for me (TW2, BF3, Metro, maybe a few others?). The game still looks great completely 'stock' and IMHO blows-away anything else around highly-modded.