And growing! Rapidly! Good thing they spammed all those transactions ;). They need to produce blocks that frequently if they want to deliver the kind of performance they are claiming EOS is capable of. Imagine someone wants to string together 20 smart contracts all of which need to be executed sequentially, before funds are transferred. That one transfer is still going to take 10 seconds to occur even with .5 second block times. Had they chosen 3 second block times... well you can do the math. Not saying it's a bad solution to the problem they're choosing to tackle, but it highlights part of the reason we're so committed to application-specificity. For Steem, 3 second blocks work great and few see any reason to increase that rate, especially bearing in mind that doing so would only make the chain grow faster.