There was more to it than just paint and fat tubes, some things that Kleins* had in the 80s/90/s
> Massively oversized, thinwall and butted Alu tubing
> Internal cable routing
> Pressfit Bottom brackets
> Integrated Headsets with oversized steerers
There was also the fact that they rode differently to most other things out there at the time, as well as being very light and very bold visually in an era where most bikes were skinny steel with 1 inch threaded headsets and quill stems.
As with most things like this they divide opinion, and as with most things that divide opinion both sides have valid points 😉
*yes there were some others too that did some of these things, and earlier, but the only guys really doing them all, and successfully, and with flair were Klein.