I agree with this. While it seems that the general rule is to be concise, it is really important that applicants make sure they understand what each specific program wants. My program required the essay to be 6-10 pages double-spaced. They also had a very specific resume template they wanted applicants to use and stated that it should be as thorough and detailed as possible. I had to contact them, because thorough and detailed do not go along with my standard conception of a resume, but they told me that they wanted as much depth as I could give them, so that they could gather a better understanding of my experience and they stated that resumes for their program were generally at least 3 pages.
On the other hand, most of the programs that I researched had much shorter requirements, if they specified length. This is something that applicants should be careful about, because it is better to give the specific program what they want rather than assuming they will want the lengths that seem to be more standard. If a program doesn't specify page length, it doesn't hurt to contact them, just to get a better idea of what they are expecting.