Why Should Racism Still Exist in this Internet Age?

Regardless of race, social strata, religion, economic status, we all are driven by our attitude. We act on something because we were driven by our gut feel or a mindset. We have our own biases; and our instinct dictates our judgment. 

Let's focus on something close to our common experience - the online writing communities and job boards. I have contemplated on these matters myself, so I'd like to share these questions with you as well.

When we join a website and see many members join, do we see that as a sign of growth or something that will lead to its downfall? Do we see a new member as an opportunities for growth or a competition?

When we meet other people who are not of our race, do we shut them out or welcome them. For what reason - because we tend think this or that race is friendlier, or kinder, or more obnoxious, or a bunch of bigots?