I don't why people tell men to be more vulnerable.

A vulnerability is literally a way for people to exploit you.

There are two variables to exploiting a vulnerability:

  1. Having one
  2. Being aware of it. (World is now gaslighting people, "You should talk about your vulnerabilities")

Anyone with any more of first principles thinking will see this common trope as essentially gaslighting people to expose themselves to get attacked. Imagine that telling people to talk about their vulnerabilities as a good thing...

Something that has high vulnerabilities and have been exploited, guess what you lose trust and respect.