If Google sells me ad-space - or a Nexus - and then doesn't respond when I have a problem, that's bad. But if your pages drop in the search result rankings, suck it up and maybe pay a bit more attention to the spirit of that preaching - Google owes you ZERO customer support if all you're paying for is snake-oil from some 3rd-party SEO "expert".
Meanwhile the world commerce is moving towards the Internet and Google controls 70% of that. But you don't want to come off as "spammy" so better to risk your company and follow the rules of an unresponsive search company that might or might not punish you for it.
Are there examples of sites that have done no SEO, and can still point to a banning-type event in their search result ranking history? Obviously this wouldn't be a big site; it might just be a random business the marketing of which is mostly offline.
...so you gotta do what it takes to get ahead, even if that means abusing the system and everyone else who depends on it? That's been the spammer's argument from Day 1, and it's just as crap now as it was twenty years ago.
No one owes you a successful business. If the only way you can find to make money involves dumping on others, then you shouldn't be surprised when there are consequences - even if you're following the "letter of the law" while doing so.