Finishing, as in will power, focus, and vision, is like a muscle that you can take to the gym.
This advice is the equivalent of going for a run one day and never picking up the habit. I don't think it will lead to fitness.
I like open source software. And I could write some code that works for me, then generalise it to be useful to more people, then increase the robustness so it's easier for users who aren't the author, then clearly document it, then make a flashy website for it, then do branding and marketing to get users, then add support for OSes I don't use and languages I don't speak, then build a community of contributors and maintain a presence on reddit and twitter and stackoverflow and discord and github and mailing lists, then engage with the community with polite professionalism at all times, then do paperwork like choosing a license and a code of conduct and a security policy, then convince major distributions to package it, then maintain it for 30 years.
So long as it's a recreational hobby, I'll do whichever steps I feel like. Marketing? Support? Fundraising? Test coverage? Nah, I don't think I will, I'd rather spend that time going on a bike ride.
On the other hand, for things that aren't a recreational hobby? That might be a different matter.