I try to give everyone a chance if they at first show their ass, but after that, I will never respond to them again. Every one makes mistakes, god knows I have made my share. I will say I totally agree with your sentiments on the subject.There is no accounting for the depth of ignorance certain individuals reveal on the internet. My belief it is related to anonymity. I try to not engage with such folks because they are beyond help -- they will not, or cannot, learn. GB Shaw said it all, "Never wrestle with a pig because you'll both get dirty and the pig likes it."
Take care.