Why do you think Canada wouldn't be as good for Central or South Americans? There are flights to Central and South America from almost everywhere in Canada. I speak Spanish in Canada often.
Most of the TSA people I know are normal people and have families,kids and stressful job with passengers being aggressive at them for no fault of theirs.
TSA employees are free to quit and find another job that doesn't involve fleecing the public to create security theatre, harassing people for no good reason, etc. They choose not to, and they are responsible for their choices.
The US does not regard this as a valid excuse. Cf. the Nuremberg trials.