It's not about the number of ideas. It's about the time it takes to complete multiple projects. It causes delays, and extends the amount of time a game spends in development.
This, by default, means that your Patreons end up paying more than they otherwise would for the development of the game.
This has become a practice of nearly epidemic proportions in the genre. As if Patreon didn't fuck it up enough already. Hundreds of devs pretending to juggle multiple projects, with nothing more than excuses usually to show for it.
THAT is the problem.
I guess that it's a good thing that you have a job that pretty much nobody actually cares about you doing. Maybe I'm just salty because when I go to work, I actually have to work. I don't get the luxury of saying, "I don't wanna save lives today. I'm just gonna catheterize everyone instead!"