Ugh, this is always the dumbest argument brought up when saying someone isn't a great prospect. I'm a fan of Zabit, arguably the top prospect in the UFC, and who has he fought? A bunch of nobodies too. How about Taisumov? Gillespie? Costa? Don't tell me his win over a shot Hendricks was impressive and gave him credibility over any of these other guys.
And Matthews' performance against The Leech (a more legit fighter than any of the other guys have fought) was outstanding. Apparently you must not have watched it and assumed it was boring since it was a decision.