Ah a fellow music nerd (willingly or not haha) is here!
I don't really agree that they're 'ignored', they're just acknowledged as suggestions rather than rules. The basic western harmonic system is pretty much unchanged at the foundations, and just evolved beyond it.
It frustrates me when guitarists have this constant philosophical war against music theory. They just end up feeling lost and confused when they can't figure anything out and everything they do sounds bad X(
But yeah this particular area of music education is pretty unnecessary for 99.9999% of musicians