Good article. I will be printing it out for my personal library.
One saying of O'Sensei's has been translated to mean "defeat the spirit of contention within".
As this article points up, just because someone is being judgemental, does not mean you have to accept their judgement.
I do feel strongly (as if you couldn't tell) that the spirit in which one approaches their training will determine the quality of their training and how the treat their partners. Those who train solely for themselves, while they may improve their technique may also cripple their spirit.
No one gets good by beating up beginners.