Agree to disagree. Plenty of room here in the sandbox.
I started out some years ago with a few bikebugs (grossly underpowered friction drive) and had enough fun to keep going... next were China girl engines and I enjoyed having more power, but poorly made parts and the crapshoot on whether the engine was decent or not, along with way too much vibration for an old guy with tired hands led me away from them and into the smoother realm of four strokes. Not that I don't have 2 strokes... just no more China girls.
As for centrifugal clutches, they have their place and I have a couple of bikes using them, also one with CVT another in progress which will be lever operated manual, another with a wet clutch on a 1934 Sachs 2 stroke and a dog clutch on a trike I'm slowly building. One kind of build is happy with one kind of clutch and another wants something different.
Things purchased ready to assemble out of a box are nice when you're starting out in this madness (hobby, I mean), but once you start fabricating and inventing then things from kits pretty well lose interest. Being somewhat difficult is what makes DIY builds fun and interesting. One of my favorite builders here is cannonball2 as every build is different and inventive. Clever, fun stuff. One thing I try to avoid is getting too serious about what should be fun. Diversity is something to celebrate. Beautiful if great, but so is weird. I'm now finishing up a strange alien creature from a MTB with a rack mount 79CC Predator, jackshaft and final drive being a salvaged 3 speed Sturmey Archer hub used as a friction drive. It has been lots of fun and interesting and is also the weirdest and ugliest bike I've ever made. I love it. Ha!