"As for
SEO (and I know it’s not the purpose of this blog... but common, isn’t all related?), I learned with the years to be cautious with what Google want you to do and what really works on search result pages."
I've a similar conspiracy theory related to Google's disclosure about how their inner cogs work, specially on topics related to
SEO, where they algorithms are or could be abused.
I think it's "good" to give some misleading advice.
If they would have published something like this: "static URLs are the only way to get indexed, and dynamic urls will be discarded from our indexes", then static URLs would be the new
SEO panacea and will be used and abused by everyone, particularly snake oil SEOs.
Imagine it: lot of websites rewriting their already-working dynamic URLs into bad rewritten (because of ignorance) static URLs, making a worse scenario for crawlers.
But then, Google knows *there is good valuable content behind dynamic URLs*, and there is no reason to discard them just because the URLs aren't "pretty".
Probably (in fact, that can be read between lines in Google's article), indexing dynamic URLs (and at the same time, avoid indexing duplicate content) has higher costs for the Google machinery, and so, they lost time and money trying to find out which variables lead to the unique content they want to provide on they
SERPs.
And then, it get worst for Google: it's easy to strip out variables from a dynamic URLs until you get the "minimal functional URL".
But it isn't too easy to do the same on a static (bad) re-written URL: it may lead to 404, it may be "impossible" for Google, then their costs on crawling/indexing become higher.
So, at the end of the day, my conclusion (my "conspiracy theory") is that Google is trying to _separate the wheat from the chaff_: the people who does the homework, both for having more human-friendly sites and for
SEO's sake, and the people who doesn't care about technology friendliness,
SEO, or those who abuse it, or those who does it in the "wrong" way (without anyone really knowing which is "correct" one), like doing bad URL rewriting.
So, the advice here is: don't do it if you are going to do it wrong.