People who are insecure make bad, irrational decisions.
(...)
being insecure causes you to make decisions based on fear, and people
who are motivated by fear alone cannot embrace a big, disruptive
vision. They end up being fundamentally risk-averse and drive you to
be too. (...)
Even worse, you can't honestly call bullshit on people who are
insecure without undermining your relationship with them.
People who are secure, on the other hand, like to be challenged. They
enjoy vigorous debate. The intellectual swordplay is what they live
for.