Why does everybody get so excited about pagerank?

A high Google PageRank score is greatly sought-after, yet its not the most important factor in a site's ability to rank well in search engine results pages. So why do people get so excited about PageRank?

Here's what Google has to say on the matter: PageRank reflects our view of the importance of web pages by considering more than 500 million variables and 2 billion terms. Pages that we believe are important pages receive a higher PageRank and are more likely to appear at the top of the search results.

The key words in that sentence are 'more likely' and '500 million variables'. The implication is that site A will rank higher than site B if it has higher PageRank - all else being equal. But the various factors that go into a search engine result page are never equal. How can they be when there are 500 million variables to consider?

My viewed (based on experience) is that Google is more concerned with relevancy than its own scoring system. If site A is more relevant for any given search, it will appear above the less relevant site B in spite of their respective scores.

You can get your site onto page one of Google for a specific keyword phrase even if you have a low score. What matters is how relevant that page is to the given keyword phrase.