They seem to emphasize that xenForo is just a forum. With forum-like things in areas they shouldn't be. Plus it's just junky.
I think it would be a good idea to make the breadcrumb easy to TOGGLE OFF or ON for certain tabs. Style designers please make note !
Update: This post shows you how to get rid of the breadcrumb.
Update: April 20, 2011
Breadcrumbs are useful for navigating nested forums, galleries with hierarchical categories, a database with hierarchy, and catalogues with nested categories.
The more nested the information, the more the breadcrumb helps.
For Information with no hierarchy / nesting ... breadcrumbs do not provide any function.