So maybe I'm not explaining my view very well. 106 generally has one of the highest forfeit rates. A lot of schools just try to find any kid who weighs less than 106 (usually a freshman who hasn't started growing yet) to get forfeits. If we started at 113 and added a weight in the middle or upper weights now that Varsity spot would be filled by a bigger and in a lot of cases a more "varsity" ready athlete.
And to answer your questions...
If they’re great, why throw them on jv? Not throwing them on JV. If they are a JV level wrestler then yes they could be great at the JV level (maybe this is a philosophical difference as I don't see greatness measured in Ws and Ls but rather everything else gained from being a wrestler - hard work, dedication, sacrifice, discipline, etc. You can achieve greatness in these areas without being a state placer or champ). Putting a 100 lb kid with no muscle tone on varsity seems more like throwing them on varsity rather than throwing them on JV if they are truly JV caliber.
Would you rather have guys like Cernus and Cottey on jv? No. They would most likely be on varsity just at 113. They could cut less weight and I'm pretty sure they would still be great.
What I would really rather see is upper classman get more opportunities to be a varsity athlete. 100 lb freshman getting to be a varsity athlete because he is the only one that weighs less than 106 over a junior or senior who is a back up wrestler in the middle or upper weights but is still pretty good.