I think some people associate the word marketing with lies, scams, and whatnot. What if we view the word marketing as a way to market products in a more neutral sense.
Can his honesty a marketing material? why not? it depends who reads it.
A message can be a marketing material regardless the intention behind it.
> The difference between DHH and others is that he's actually practicing what he preaches more often than not.
I think we all know that otherwise we'll call people who don't practice what they preach as a not-genuine.
> They actually believe this stuff and don't mind sharing what they think.
Most people believe on what they build/working on, otherwise it's a one-trick pony and it takes a lot of guts to work in such place especially for engineers.
The difference between DHH and others is that he's actually practicing what he preaches more often than not.
While 37Signals are brilliant marketers, not every opinion is marketing speak. They actually believe this stuff and don't mind sharing what they think.