Audette's POV is built on a number of factors--the first being that PR is still a gray area when it comes to Web sites. Marketers don't know how much PR a page
or link actually has in any engines' eyes--and thus don't know whether they're making a positive or negative impact by sculpting.
Meanwhile, time spent sculpting PR could actually detract from the time an SEO takes to work on factors that can have concrete positive results. Sculpting can also mask larger architectural or content-based issues. In addition, PR sculpting focuses too much on the engines--and not the user experience--which, if focused on and improved, will likely have a greater impact on PR than any amount of internal link juicing.