First off, they're marketing SEO services and products and marketing themselves as 'SEO gurus' for the Internet marketing trade show speaking circuit. As such, they have to tow the Google party line and get the "Google Seal of Approval" on what they say and do in order to keep this status. There are other SEO companies/consultants that work very quietly and discretely but some others find it better marketing to blow their own horn constantly and attack others for doing the same thing they're doing under the covers.
You also have to consider that they are also competition for anyone offering SEO services and, therefore, are unlikely to offer anything that's truly actionable and will tend to use misdirection and obfuscation about what's really going on and what they're actually doing. They aren't going to tell you that they're discretely buying links and creating private link networks. Instead, they'll use tall tales about the power of the Google AI "quality content" algorithms and suggest mostly useless on-site SEO tweaks.
Also, they're primarily concerned about SEO client contracts, especially with mid-sized to large corporate clients. These clients do have good reason to be cautious in their approach to SEO. After all, if you're a moderately big company, you don't want your corporate flagship site to be penalized or even deindexed or your reputation harmed due to wild and crazy SEO tactics. They market themselves into this niche quite well. Of course, it's to be expected that they don't practice the "churn and burn" strategy that most niche affiliate site marketers use. It's kind of like comparing managing an indexed mutual fund
to day trading
. The same basic thing is being done, buying and selling stock, but the methods, rules, risks and rewards are very different.