I understand what you're saying. And I would say if that's what someone wants to do for sure I wouldn't criticize them.
My criticism is most certainly with Krylon and Rustoleum. Krylon is not designed to work with any other product or even their own clear coat in some cases. It does not last very long, and it does not have very much pigment in it at all. So it seems like you're saving money, but not as much as you'd think. A can of model Masters Paint from testors has more pigment in it than a whole can of Krylon. It goes on smoother and dries
Rust-Oleum makes a few good paints. Specifically the hammer tone. When it's a fresh can you can use it and it'll dry in a decent time and be a pretty good finish. Again not much pigment compared for the size of the can, and it doesn't last very long.
Again just my opinion from my experiences painting a lot of different stuff. Enclosures, RC model aircraft, cars, guitars, etc.
I respect your disagreement. It is all personal preference.