I think what he means is that on forums people tend to concentrate on PR and not alexa or any other. You could have a PR4 but poor alexa. Is that what you mean op?
As you say there are a lot of pr 5 websites ( for example ) that are not even in top 100000 in alexa ...
If you go to BST some people ask for link sales on high PR sites, but don't seem to get response. People want traffic, more than PR I think.
I think PR is useless because my site got 3 page rank and after geting 3 page rank my per day visits decreases.
It could be a coincidence your traffic decreased. Remember that the toolbar export of pagerank is a snapshot of the value a week or two before. Prior to that you may have had PR 4 or 5 - if you were lucky! - which then dropped to 3. Also, some traffic is seasonal. My site has taken a drop in traffic in the past couple of weeks due to the holiday season.
old time ....PR was an old and helpful tool which was related to serp directly. now PR affects market getting smaller than before ....
the problem is a page has more backlinks do not mean the page can become more important now the days for web users
I don't think that Google will include PR if it has nothing to do with their algo itself, Google base the importance of a website through PR....
Have a Deep Look at: http://www.google.com/corporate/tech.html and than please don't post any more about PR is important or Not. If you are really a good reader than you will understand what Google wants to say... If not dan It must be your bedluck...