I don't thing Parent was talking about business at all. Personal projects are not things you do because of potential business opportunities in my book. I wrote a GameBoy emulator, several raytracers, countless demos on 8bits machines, countless "IoT" things, an automatic cat feeder, a 3d scanner and much more, I never ever had the goal to transform that into money, that was for fun.

Of course you won't write anything that you hate at first, because it's for fun. But hating something for some days or weeks is part of the fun, too. You are challenging yourself, not doing it the easy way, to appreciate how well the others are doing.

If you want to turn it into a business, so yeah, don't write a graph visualization engine, or crypto stuff, or anything really. Get a job, that can be fun too, and let the entrepreneurs figure out the rest.