Why would our mainstream culture and religion drill it into us that 666 was very negative and to be avoided?

Why does 666 get all this hate, when almost all inspiring buildings and architecture hide 666 in their geometry, all the way back to Ancient Egyptian /Sumerian et al times?

What if 666 was simply a way to harmonically resonate success/benefits/blessings for the people who make use of it somehow?

What if we were told that it was bad so we wouldn't use it?

Any opinions on this apart from it's the mark of the beast? (which I've already heard a million times, thank you). Anyone knowledgeable here could shed light on its properties as a number?

Thank you.