I think it's concentrated on too much. People spend ages chasing down links from irrelevant, but high PR pages, when they'd be better securing a quality link on a low PR, but very relevant page.
I think its a serial pack that people know what is his serial of different site. And if a page rank is high then that site is well known to everyone.
If you are too much bothered about Page Rank, then you must read Matt Cutt's post on the topic where he reveals that Google returned random page rank for certain websites (not all of them). He is the head of Google Web Spam team and he reveals this information purposely to let people know that PR is not the end of SEO and relevancy is the key factor you must concentrate on while building links. Even if the PR is low, links from relevant sources adds value in the long run. Anyway, high PR backlinks still have a lot of value in SEO as a whole. If you want to know more about PR, then you must read posts of Cemper.com which clear all the myths about PR.
Well Said, PR is not a matter of worry as if you have build a good website and post useful information on regular instance than you are bound to get number of hits leading to increase in popularity of website. This will fetch you with some natural inbound links and by the way increase in PR. Google Considers number of factors to allot PR to any particular website.