Why do programmers choose to write their own code instead of using code that is already available online?

Read also:

• Why do nice guys rarely or never win?
• Do airline pilots try to avoid turbulence? How can you tell if your flight has been rerouted due to weather conditions or other factors?
• What life lesson did you learn the hard way?
• Have you been with a stranger yet?
• What's the funniest thing you heard in a movie theater?
• Why do I want to suck cock, after smoking methamphetamine?
• Why does my crush always looks at me in a sad way whenever I talk with other boys, and if he catch me staring on him then he go and flirt with other girls and then check if I am looking at him?
• This Week In Space podcast: Episode 165 — Guardians of Space - Space
• Is there such a thing as "left wing fascism"? If not, what is an example of a political ideology that is often mistakenly labeled as "left wing fascism"?
• What are some of your favorite hip hop lyrics?
• Which fish tastes good for South Indian curries?
• Why is the US going after Canada after all? What is the reason for all this hostility?
• What options are available for obtaining prescribed medicine if you are in therapy, do not have insurance, but need them for functioning well?
• What are the coolest new smart home gadgets to upgrade your living space?
• Is it right to visit any shrine or tomb in Islam?