To be fair ... the 21st and 24th centuries are only a few hundred years of human evolution .... compared to the 40,000 years prior where we spent most of our time fighting one another for power and money with clubs, swords, and our bare hands.
I wouldn't expect us to behave any differently for a few thousand years before we could change significantly.
Just because we can fly spaceships and have advanced technology ... doesn't mean that our minds and behaviour evolved as fast in a few hundred years.
"And if I had to do it all over again, I would. Garak was right about one thing – a guilty conscience is a small price to pay for the safety of the Alpha Quadrant."
Worked out for him, he got to avoid feeling guilty by becoming a wormhole alien.
After seeing that article about how Navy SEALS all have severe brain damage from being around constant explosions, I do find myself questioning the real value of these elite soldier and spy organizations. The defensive counter-espionage could be done with more scrutiny and transparency (which would arguably make it more effective). And maybe destabilizing and overthrowing foreign governments is uh... bad... actually.