Not so easy to enforce, because most ticketing systems don't require the name of every single attendee. Adding that requirement would be really really bad for the sales funnel, and also require tickets to be 100% non-transferable.

And much less disruptive to the target, because they get told in advance and don't drive and park and go in and plan only to get kicked out.

I don't think that was a question and it has nothing to do with enforceability.

Of course banning people based on where they work is bad for business.

You brought up enforceability, so I addressed that. The policy itself is also bonkers, I agree.

Not me, the parent I replied to ;)

https://news.ycombinator.com/item?id=34075624

But I think we are on the same page anyway