Earlier quoted context omitted.
You're confusing paid advertising with marketing. Marketing is interweaved in almost any business activity. No marketing means you literally register a company and then wait in your house for someone to randomly walk in and pay you for you services. And if that miraculously happens, you treat them as badly as you can and do the worst possible job, just to make sure you don't inadvertently get some word of mouth refer…
This is a good point that I'm glad you called out. Having a logo is marketing. Having a website is marketing. Every blog post, tweet, like, reshare, etc. is marketing. This comment could be considered marketing if you look hard enough.
Product, price, place, promotion.
All of those are marketing. Yes, even the product itself is marketing. When people claim they are not doing marketing, but going by word of mouth, they are using the product itself as marketing.