The biggest problems with "reading things on the Internet" is the GARBAGE outweighs the good by about TEN to ONE(especially about SEO) and there are far more people who spread around the junk than there ones that heed the the good advice and pass that on.
Maybe that's because making it sound difficult and far too complicated for mere mortals to comprehend is far more attractive than the fact that it IS ludicrously simple. There are no "rules" to learn, no secret sauce, no scientific principles that you need to know and above all, no exact formulae or recipe that you need to adhere to.
ALL you need to do is create a website that YOU would be happy to find when you search for information or a product then promote it to people like yourself.
You probably don't like 'pushy' sales 'persons' ramming what they are selling at you time and time again when you are listening to them, so WHY would you think that your prospective clients (the ones reading your documents) want to 'hear' you battering them senseless with the same words and phrases over and over.
It does NOT reinforce your message, it makes people 'switch off', search engine engineers understand this so they do not want THEIR customers to find documents that annoy them any more than YOU want to come across documents that are going to annoy and frustrate you. You probably won't remember the document URL that DID wind you up, but you will certainly remember that it was Google that showed you it, therefore it's all Google's fault and you are then just a little more reticent of Google results in the future and therefore less likely to 'trust' what they show you. Which has a knock-on effect that affects the possibility of you clicking through to a advert that Google gets paid for.