First off, I don't remember CLG ever "bashing" NA. They said things that, as you said "is a fact." NA is a much weaker region than Korea, and scrimming in Korea is better than scrimming in NA because the teams are stronger and they take them much more seriously than in NA or EU (for example look at that Hjarnan interview where he said that H2K, a strong EU team, "doesn't give a fuck" in scrims, that's something you would never see in Korea, and if a coach did see that, he would make the player stop that shit quick). The only person who has tried to bring up any examples of cockiness or bashing was /u/Bodytags with this link (https://twitter.com/MarcelFeldkamp/status/489249107907588099), however, he just was saying how much more helpful scrimming against stronger teams is a lot more helpful than scrimming NA and EU teams (and before you say that they were still shit after these scrims, realize that no nature of godly scrims could have saved the team from their shitty atmosphere and personal issues).Sure he might be exaggerating quite a bit, but even then it seems ridiculous to call it cocky to exaggerate the quality of Korean scrims, last I checked, cockiness usually pertained to your own skill, not what you thought about how well Koreans scrimmed.
Also, saying that Cloud 9 is the only team that has any right to acknowledge "the fact" that KR > NA is just wrong. You don't have to be part of the number 1 team in NA to acknowledge a simple fact. Is Montecristo not allowed to compare NA and KR now because he isn't on Cloud 9? Why do you have to be the best in your region to objectively analyse and compare you region to another? I just don't see the relationship there. If you want an example of bashing on your own region then you can see this: https://www.youtube.com/watch?v=hZxPEidg_Dc&t=3349. But even in this case where Crumbzz, a person who left a bottom of the pack LCS team and is now on a challenger team, says that "NA LCS is actually garbage" I still don't hate on him for it because I can recognize that just because he thinks NA is bad does not mean that he automatically thinks that he is better. This is where I think why so many people got pissed off at CLG for practicing in Korea, calling it cocky and whatnot. 1st, they thought that CLG said that NA was shit, which as far as I can see, they didn't. (If you can prove me wrong on this one then fine) and 2 they think that because in their mind CLG said NA was a weaker region (even though I don't recall them saying this) that CLG immediately thinks that they are better than everyone else in it. You can recognize that something is bad without thinking you're better. For example, I can say that Unlimited is a shit support and still know that I'm worse than him.
Overall, the move to Korea to me was one of desperation, not cockiness. They knew their team was shit, they didn't think they were good, there's a reason that they put so many resources into training them, because they knew they were a shit team at the time. For me, it was more of a confession of their shittiness and a miscalculated desperation move to get any hope of making it to worlds, not them thinking that they are suddenly the best team in NA after a huge losing streak with a shit team environment.