Because they pay under $20/hr, offer no health insurance, dental, no vacation, termination at will, and little possibility for promotion or advancement of skills. That and the balance of power is entirely skewed towards some MBA in a monkey-suit sitting in a corp HQ palace hundreds or thousands of miles away, who only looks at numbers on a spreadsheet or pretty pictures on a powerpoint that represent the lives of human beings. It's not only coders who should never be called "resources"—the same basic decency applies to all humans.