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

Read also:

• How can I fall asleep fast at night?
• You hold the door open for a lady and she stops in her tracks and screams at you, ‘Don’t hold the door for me! I’ll get it myself!’ What are your feelings or immediate reaction?
• Is Daenerys Targaryen really the most beautiful woman, or is everyone saying that just to flatter her?
• Why do humans sweat while stressed?
• Jenny from Perth writes – my partner is the life of the party, women and men adore him. But at home, he gets angry at us for the silliest reasons and never nice words me or our kids, always putting us down. Should I stay or leave him?
• Why is the government destroying the homeless instead of helping them?
• Have you ever had a weird experience immediately following the death of a loved one that made you think there is an afterlife and that the deceased person was communicating with you?
• As a NATO/Ukraine supporter, since you're so blown away and angered by Trump putting Zelensky in his place yesterday, why don't you support the Ukraine by joining the Ukrainian army? There's 200,000,000+ of you. Put your money where your mouths are.
• How can a hacker damage me, realistically?
• Can a Trump supporter explain what was wrong with what Bishop Budde said to Donald Trump?
• As a friend of Megan's who also watches Suits, would you advise her not to return to the show in order to protect her character's reputation?
• Do you agree with Kamala Harris that Donald Trump is dangerous?