It's not a waste of time if you had fun working on it and if you learned something from it. If someone has no intention of finishing a project yet put time into it, then not finishing it is according to their plan and by definition not a waste of time to them.
Basic lessons learned: It's the journey that matters, not the destination. As well as learning from past experiences, whether they were successes or failures. None of that time is wasted.
I mean, we could get into platitudes if you want. I'm not really a fan of them as they're there just to make people feel good about behaviors they otherwise wouldn't...
Let's say you're right. For the sake of argument.
So, you create a new project, you learned all you could learn from that project in the first 5 hours, but continued to create that product for an additional 300 hours and it never sees completion.
Doesn't that mean the other 295 hours are wasted?
We are humans, we have a finite amount of time on this planet. Any time we spend is time we do not ever get back. If you gained nothing with those other 295 hours, couldn't you have spent that time doing something more productive? More fun? More personally enriching? More in line with your personal goals?
The journey only matters if the destination is worth reaching. There's a difference between a journey to paradise and a journey to a boring place you don't want to be.
I've heard that phrase quite a lot in the writing industry, by the way, and always thought it was somewhat... disingenuous.
"It's the journey that's important". No, it's not. The entire journey can be ruined by a destination that doesn't satisfy. It doesn't matter if you've written 3,000 pages of pure gold if the last 4 pages utterly undermine everything about the journey and do not conclude things in a satisfying way.
Real life works the same way. It doesn't matter how your own personal journey was if it ends in a depressing hate fueled drug binge of you destroying your own life. It's sad, but it really doesn't make your life worth much to talk about other than, "Yeah, don't be that guy."
I received two bits of amazing advice that wasn't even directed at me when I began writing. "Beginnings are difficult. Where do you start?" Deciding where you are starting on any journey is important. Because deciding where to start ultimately decides the overwhelming amount of content of that journey. The other is "Endings are hard". Deciding where to end your journey is also difficult. Everyone wants and needs closure. A perpetual journey isn't interesting. It's why we have chapters in books. Everyone needs a place to end a story so they can begin the next one. That ending doesn't have to be perfect, it only has to wrap things up nicely enough.
People on a perpetual journey or who value the journey over the place they end that journey ultimately have no goals to strive for. They achieve nothing. Acquire knowledge for no reason. They become well-built ships locked on land with no ocean to sail on.
All through wasted time.
These people attain knowledge, but never develop the ambition to use it. They flounder about. Waste time. Don't chase their goals. Muck about with things that aren't helping them achieve their goals.
There comes a time when everyone needs to accept their own limitations. If you want to create artwork and are using creating new RPG Maker products as the excuse to do so... you're hurting yourself. You don't need the engine to do that.
I don't need the engine to write stories. I don't need it to write books. I don't need it to create characters. I've known I could do all of that long before ever even messing around with RPG Maker 2000 back in the day.
The reason I am drawn to RPG Maker is because I genuinely enjoy the experience of creating a video game. I love the unique writing style that creating a game is (it's like writing plays, but different in many ways). I love creating the systems players will interact with. I love seeing just what players will do with what I've given them. I'm not making a game because I want to write. I'm not making a game because I want to prove I can do something to myself. I'm not making a game because I want to interact with people on a website. I'm making a game because I enjoy the entire process. Even if that process takes me 10 years to produce a game, I won't mind.
But, let's say I do work on that game for 10 years. Have I been wasting my time? Not really. I work on it here and there when I have time or drive. I'm focusing my energy elsewhere. Getting a good job, earning pay raises, managing 14 employees, building a better resume, looking to build credit and cash in order to buy a house, so I can get a couple cats and get out of the tiny apartment I live in. I'm aiming for my boss's job at work, or something similar to that. I'm aiming to be able to pay for everything I own and genuinely have quality products in my life rather than "used" or "hand-me-downs". I'd like to buy a brand new car someday without taking out a loan. I'd like to have a nice kitchen that I can cook some really great food out of.
But, I also want to make a game. It's low on my priority list. It isn't always fun to work on. I slash anything in it that has become a "waste of time" rather than try to get it to work. I vet new things in my game to see if they would be a waste of time if implemented.
I don't want to get to the end of my life and think, "Man, I wasted 70,000 hours of my life building a game that never got finished. I could've learned a new language in that amount of time... I could've dated more... I could've went traveling... I could've played more video games... I could've read more books... I could've made a difference in the world somewhere by volunteering my time."
But, some people are comfortable wasting their time for no reason. Knowledge without ambition.