Why do people create Heartbreakers?

Although I have been playing TTRPGs for 45 years, I had never heard the term "Heartbreaker" until I joined this subreddit. The term is used so much here I realized I needed to google what it means.
I discovered it is in fact an insult. A "Heartbreaker" is a "new" TTRPG that pretty much is a copy of an existing TTRPG (usually Dungeons & Dragons). It's a TTRPG that really has nothing original. Basically, it is just the same TTRPG with some house rules added.
But I read here is people posting things like "I have been working very hard on my Heartbreaker". Why are folks working so hard on something they expect to be unoriginal, and not good?
If you just want to add some house rules to an existing TTRPG, go ahead and do so. You might even post these house rules. Or if you have some new ideas for a setting for an existing TTRPG, go ahead and post those. But I don't see why anyone would work hard on just writing over again all the rules of D&D just to include their own house rules.
EDIT: Interesting discussion. I am glad that one or two of you provided the link to the original "Heartbreaker" article: http://indie-rpgs.com/articles/9/ I hadn't read and found it before.
Although some of you disagree with me, I am still largely sticking to what I said in my original post.
I have only "published" one TTRPG product. The Solitary GM, available on drivethrurpg. That is not a Heartbreaker. It isn't a complete game, it is an add-on that you can use with just about any TTRPG. Now, I could have invented some sort of generic "Heartbreaker" to surround the idea, to say "You use this system as part of this other game I created", but I didn't. I genuinely believe my product was based on an original, innovative idea. At least I had never found anything like it in any of the games I have played in 45 years, or could find online. It was addressing a problem that I hadn't seen anyone else address. That is my response to folks who are saying "nothing is original".
A lot of you are saying "but I don't want to make money". That has nothing to do with the point I was trying to make in my original post. My product will not make me rich, but I posted it to drivethrurpg anyways. I never expected it to make me rich. If you really don't want to make money, and are just doing it for your own small group of players (which many of you have said), why work so hard? Edwards original article says that yes, there is usually at least one good innovative idea in these heartbreakers. Usually the magic system. But the "nugget" is buried among the derivative stuff. If you have come up with a better magic system for your favorite TTRPG, that's great. Write it up as an optional rule for D&D. Maybe even post it. But why go through all the trouble of copying ALL the rules to D&D just to surround your new, original idea?
And most professional TTRPG writers get into the business that way. They start by creating additional content for already established games. They come variant rules, new monsters, new scenarios, new spells, new magic items, and so on. That is an important part of TTRPGs. Often we find supplement books that are written by somebody other than the original author of the game.