"Code aside .... IMO tywraps are 'temporary.' Even indoors, give them a few years and they become as brittle as glass."

I cannot predict the future! Nor, could any other inspector.

"What might be fine for hanging a few phone lines from the steel trusses above a drop ceiling might not be so smart when you're hanging a 12-pc bundle of #8-3 MC or 4" EMT."

That I agree with you on. I have yet to see anyone try that!!