Interesting reaction. What's your thoughts on why when you delve into it?

Could be too personal to share no worries! Ha :) But I'm guessing because the lack of decoration, could be linked with lack of friendly consideration to the people about. And the blocky forms could seem imposing and gigantic versus human scale. Combined it could give the impression of something authoritarian, like a penitentiary or Orwellian government ministry building. You might be feeling uneasy about its obvious display of power.

All this makes me think: maybe they should remake the Pentagon in brutalist design. To, just, like...be really unobvious about it. Hahaha! :)