I'm not so sure JK actually did anything for youth development that wouldn't have happened on its own… except hold up a mirror to MLS and USSF and reveal its shortcomings.
I think he was 100% right about the mentality of players choosing the easy path and picking MLS when they were good enough for Europe.
"If you play in an environment, where if you lose Rangers against Celtic, you don't want to go to the baker the next morning. If you lose that game in Salt Lake City, it's different. I don't think somebody will bother you about that. They'll say, 'Oh, you lost last night, but no problem.' In Glasgow, nobody will say, 'Oh, it's no problem.' They will give you crap for five days. You don't want to go outside anymore."
Players and USSF needed to hear that message. To me that's his only real and lasting accomplishment. That and being the first example of USSF hiring a top coach from abroad, which hopefully will pay dividends now the second time around with Poch.
All that said, I think he's a dirtbag not for what happened here but for what he did at Hertha Berlin. I certainly enjoyed watching him flop at Korea and if he works again, I'll root for him to flop there too.