But there's a third option, and it's the one Wheaton is complaining is no longer there.

Instead of there being a way to "like" this thing on an external social network (like G+ or Facebook), what about just "liking" it on a system that exists only on the site itself (in this case, on YouTube)?

Then after that, how about a system to Share the item? This doesn't really exist on the web, but the Sharing system on Android solves this problem well.