RIP Google PageRank score: A retrospective on how it ruined the web
I feel like no matter how Google or any other search engine ranked pages, SEO firms would be there to game the system and make a mess of the web.  Making Pagerank visible to people with one particular toolbar does seem like a fairly major misstep on Google's part.  The majority of the people who would really care about that are the kind of people you shouldn't be encouraging.One of the obnoxious things about SEO is that if one person is doing it everybody has to do it.  It's not necessarily enough to simply offer a better product at a better price.  Luckily Google does try to reduce the effect of SEO.  I notice for instance that StackExchange almost always beats out Expert Sex Change links these days.