No matter what you do, someone will have an opposite opinion. And both sides can be right at once. They both have ups & downs.
Learning new code will require more time. At this point you've already invested time learning RPG maker, and you can put that info into practical use and see what the results will be. While starting to learn something different, will bring you back to square 1. And if you want to code and make everything alone, it'll be a massive amount of work. You also have more knowledge of RPGM than your family does, so you can't expect them to understand what the engine can do.
It's true that some people don't like RPG maker games and avoid them. But others love the engine and search for those RPGM games (like me).
No matter what programming you use, it'll have some fans. And customers come in different types: some are harder to please, others buy & never play, some are obsessed with reviewing and with their "critique" persona, others never review, others send feedback to the makers while others don't. Some jump on whatever system is new. Some prefer less novelty but more refinement of the technology. On the internet there's also a whole bunch of people that just want to download things for free..
Being able to satisfy a maximum of customers will depend on the game content (the quality) but also on how it is marketed.
The marketing/business aspect is a useful part to learn, regardless of whether you use RPGM or something else.
If you're thinking very looooooong term about making games, don't get TOO far Ahead of yourself.

We've no idea what programs will be available to us in the near future and the not-so-near future. So my advice is: to use what tools are accessible to you right now, depending on your time and means, so you can make a game you're happy with and proud of. And maybe later on, you can move to something else if you think that is better.
As for the "cookie cutter" it maybe is, but it's still a great one and it offers versatility. The tough part of game making, is staying committed and finishing your games. Even if 1000 people have the cookie cutter only a handful will complete their project. So it's not so important what you use but rather to compete the games and polish the story/content as much as possible. That'll impact your success a lot.