The question of whether to trust the advice of Google’s webmasters is a difficult one. It’s something that even experienced search engine optimisation professionals are still trying to sort out. Google has a vested interest in keeping the SEO industry on a short leash, but at the same time is the primary source for information on Google.
The problem comes from the difficult relationship between the SEO industry and the search engines. The search engines are understandably suspicious of the optimisation industry. They do their best to guard against the manipulations that SEO pros devise to twist the search results in their favour. They keep their algorithms and secrets well hidden, and try to counteract any overly aggressive SEO strategies.
At the same time, the SEO industry does do a lot of good, as far as communication with the search engines is concerned. SEO pros clean up code, tighten content, and generally tidy up a site during the course of optimisation. The search engines are aware that the SEO industry isn’t at all bad, which is why they’ll never ban the use of SEO, or penalise a website for using it. Google even develops search functions with SEO in mind, warning site owners that they need to change their code to take advantage.
From the perspective of a site owner, Google does provide a lot of good advice. It’s always important to remember, however, that Google is after anything that will benefit Google. The same goes for the other search engines. If something is going to help site owners, but not really help Google, then Google’s webmasters aren’t going to recommend it. Take any SEO advice from Google with a grain of salt and ask yourself what Google hopes to gain from offering that advice.