I agree with you and Geoff on the SX part.
How can SX not have effected his confidence? He got beat; convincingly & repeatedly.
Bar his early rookie races (at 14/15 years old), 2012 SX was the first time that any competitor has truly had his number. That's got to take some getting used to, and wonder if he brought some of that baggage to the Nationals.
I also go along With the SX in many ways,when he first did SX before the GPs started last year it was an extremely steep learning curve for him,he had everything needed to win but was very raw and needed to refine things,he won in the end which was pretty impressive considering but was crashing a lot and lucky to get out uninjured
Apart from a round or 2 I don't know if he honestly expected to win coming into this year on the East coast or then the West after the broken arm,Barcia,but I really think the injury rocked him,it messed up plans,gave him a lot of free time and put him back,at 17 it was his first surgery and first major setback of his career,also along with it came the arm pump problems,I think its a number of factors why he's maybe a click away from where he could/should be,the way of racing the outdoors adding to things
I don't think its just all about getting beat for the first time,he didn't have it all his own way at many times in the GPs,Herlings gave him a big ass kicking a few times and got onto his level,Kenny wasn't so invincible afterall