How can software that is free be high quality?
Once Richard Stallman, founder of the Free Software Foundation, was asked after one of his lectures: "If free software is free, does that not mean that it is inferior to proprietary software, which is more expensive?" This is natural reasoning: people associate high price with high quality and low price with low quality.
It is important to understand that the term "free" can lead to prejudice. When one is told that something is free, he may decline to invest his time and effort to examine it, out of prejudice that it cannot be valuable.
We have traditions to avoid this pitfall. When we want to get something nice for free, we say "please." When we do get something nice for free, we say "thanks." From prehistoric times people conducted ceremonies, some simple, others elaborate, to express gratitude to the heavens for its blessings. It was believed that sincere expression of gratitude brought good fortune while failure to do so brought bad fortune. This belief persists quite firmly to this day.