3 answers to your three questions:
Because of insecurity about their own language skills.
Yes. But also because we've dared to do what many of them dare not: learn, speak and write in a foreign language.
I doubt it. They lack perception. That's why many of them are reluctant to learn a second language. Learning a second language forces you to open up your horizons, leave your misconceptions and prejudices behind and accept a different culture for what it is, not for what you want it to be.
Great article. Thanks.