Why do people make viruses?

Question

What could possibly be the reason why someone would make a virus/trojan/etc?
Unless the theory is true about Anti-virus companies making it so that we'll buy their anti-virus products... Any answers?

Answer 1

In life, there are those who create, and those who destroy. The Yin and Yang, creation and destruction. Theyre both part of the same process. some do it for the challenge, some do it for the money, and some do it for both.

Answer 2

for many reasons : fun, destroying others work...
viruses are not the same anymore.
now they are used to steal credentials(malware)
encrypt you data and demand a ransom (ransomware).

Answer 3

It's sooooo uncool to do that to other people