Lavell Edwards used to be called the closer because of how he'd make visits late in the process and get kids to commit; as time went on this didn't happen as much.
While I don't think Bronco is a poor recruiter by any means, I do think he tends to keep athletes and families at arms reach until the staff has decided they really have to have a player or that Bronco is needed to make the deal happen.
There are other head coaches that are constantly on the horn, making every possible visit under the sun, etc. (even cheating, see Lane Kiffin) Bronco is not one of those. He picks his spots and that's just his style.
The biggest impact he's made has been on setting the tone for how they recruit, who they recruit, and what message is to be sent to kids about BYU, etc. That has paid dividends in rentention and quality of player, but Bronco is not a guy that is out on the road very much. He tries to make at least one trip to the hometown of every kid they bring in, but sometimes this is at the end of the process. (see Drew Philips, Kori Gaines, Blair Tushaus for example; all had basically committed when Bronco made his home visit to them... and once he does, he hammers home the same things they had been told... in the case of Drew Philips, that meant "don't take a visit to Michigan, etc.")