Actually, when Hewitt broke him, Raonic broke right back in commanding fashion. Not to mention Raonic fought off two match points in long rallies. Though I agree with his unforced errors, too many of those.
Just remember, this is only Raonic's second year on the tour. He has actually played 1 year, as this is the beginning of the second year. Not to mention he only played HALF the first year, and still gets up to the 25th rank. Saying he won't be a top 10 player, is a little uneducated. It wouldn't surprise me if he is top 10 by the end of the major season.