Note that the blog post doesn't say "1% slowest sites", it says "1% slowest connections" - that's the mobile and satellite users. Think about how many seconds it takes to load google.com on your phone when your signal isn't great. How does taking a second off that sound to you?
Others have discussed the technical aspects of what QUIC is achieving, but you can understand its purpose fairly easily by saying "QUIC" out loud ;)
If that's not clear enough, it stands for "Quick UDP Internet Connections", which I think makes it fairly clear what it achieves. You can read more about it in the FAQ: https://docs.google.com/a/chromium.org/document/d/1lmL9EF6qK...
Note that the blog post doesn't say "1% slowest sites", it says "1% slowest connections" - that's the mobile and satellite users. Think about how many seconds it takes to load google.com on your phone when your signal isn't great. How does taking a second off that sound to you?