But let me ask you this: Do you know what a good portrait painting of a person look like? Right, it should look like the person realistically, of course... Does that mean everyone who knows that can paint good portraits? NO. Do you know what food tastes good? YES. Do you know how to make every single dish of these cuisines then? NO.
And this kind of "If I have experienced it enough, then I must be good enough to do it myself" logic seems to strangely only apply to marketing for some reason. For instance, I don't think anyone without proper training and education would walk into an accounting firm and demand a job because he or she "deals with money all the time." Unless they're crazy, I guess.
Most people (educated, and or successful people included) do not understand the delicate subtleties and the intricate planning that go behind marketing. The computer that you're using right now to read this? What the model is called and how much it's priced were carefully calculated by a group of marketers, and the packaging that it came in? Ditto.
The ad that you saw in that magazine you read at the dentist's office? Strategically placed in a section with content that would not contradict the ad's message or lead the reader to something else other than the preferred meaning AND the ad was placed in that magazine based on the demographics and interests of the magazine's average reader in order to optimize the ad's effectiveness.
All the commercial websites you go to? If it's a good enough company, the website design was carefully made in order for the highest usability to ensure the best user experience and to draw attention to the most important aspects of the website. If it was a REALLY good company, they probably have conducted focus groups to make sure the first time users have no problem navigating their websites that they are going to the sections that they're supposed to be most focused on.
Everything I mention IS part of marketing. Product naming, packaging design, brand management, media planning, product marketing... and there are so much more to marketing that those aspects, too. A lot of times, doing anything in marketing requires evidence from research, of the current market, of competitors, and of consumers as well.
It's totally fine that you don't understand what goes on in marketing, but please, do not downplay the difficulty of marketing if you have actually never worked on it or even learned about it in some way.
Here's a little anecdote: This person I used to work with in my student organization (I am not going to name him) really did not see the point of marketing AT ALL. He told me that it's like that baseball field thing: "If we build it, then they'll come." His argument was that if the product is good enough, then people will want to buy it. After he resigned, he somehow got involved in this crowd-sourcing marketing campaign for an energy drink. And guess what? He ended up apologizing to me and telling that marketing is a lot harder and more complex than he imagined.
...Why can't everyone just respect each other's job? Is it because people just think of marketing negatively? But somehow, I don't agree with giving plastic surgery unless the person were deformed, but I am not going to say, "Oh, liposuction is so easy to do! Anyone can stick a needle in someone's stomach and suck all the fat out!" The fact that you don't like something, doesn't mean that it loses its significance or level of complexity.
You can dislike marketing, but don't you dare tell me that it's easy. If it was easy, then all of our commercials would be reduced to "BUY THIS PRODUCT RIGHT HERE" over and over again, every product's name will just be what item it is (a PC will be computer type 1 and a Mac will be computer type 2), there'll be no need to have different prices for products within the same product category, you'll be wearing the same type of clothes as your grandpa, everything will just come in one color, everything's packaging will be in plain brown paper bags or white cartons, and everything ever produced will get bought, and there is no need to worry about surplus at all.
Yea, why don't you have fun with that.