Colby looked terrible on the feet. He lands because of the takedown threat, the great equalizer. But his striking is really bad. Lacks power, technique, sophistication. RDA looked like the much better striker int their exchanges, but the game is more than striking.
He has that takedown threat against ALL of his opponents. All that matters in the end is how many significant strikes you land. I agree that his striking isn't great, but it's certainly not "terrible" for MMA standards.