Of all the weird things, this riff reminded me of Hulk Hogan.
My friends and I occasionally break into fits of mocking Hogan's speech patterns, where everyone he talks to is either brother, dude, or man. Just shorten brother to bro for this riff and you got it.
I'll agree that this riff didn't have many huge "holy crap" laughing moments, but it was a very constant stream of funny, almost to the point of exhaustion. I'll give it a solid 9 for that.