Again it’s not only about mixing (reverb, delay, comp)… Yes 6 pre-insert is enought for mixing we agreed.
I guess you both know better than some of well know professional sound designer to How Create Sound. An exemple like Diego Stocco who made some great tutorial with some chain that are far more than the 6 pre-insert we have at the moment, and he is not the only one professional who work with more than 6 insert !!!
I don’t think that people asking more insert are just a luky random generation , but the technology give us new tools to explore sound. Tools such as Morphing sound, Granulator, Step FX (filter, volume, pan, etc…), Glitch, Pitcher, Stutter, Distortion, etc… Probably you both don’t use them because it’s not your style and you don’t need them.
But many areas like some music style, sound-to-video, video game, etc… really use those technics.
For “feel lucky” generation, no having a clue what they are doing" : Why not ? For mixing i agree, but for “sound design” sometime you don’t have to know in advance what the beast is going to throw, but you have to know what you are going to do with those new sounds and what they will inspire you.
For sure better know the rules, but sometime “blind sound exploration” is really fun too 
As Diego Stocco says at the end of his tutorial “The limit is your imagination” …