I think it would actually be very easy to enforce.
Let's say, when you're at registration you choose your seat from a seating chart and the seat number is then recorded on your lanyard. If someone argues that you're in the wrong seat, your chosen seat number is right there in plain sight. Sure, it might make registration go a bit slower, but a little inconvenience at the start is preferable to people just being able to steal other peoples' seats should they be off doing something. What if a group of 15 were all off getting photo ops, only to return to find several people had decided to claim some of their seats? Is it fair that the group should have to now split up to find seats when they had all been together in the first place?
Other conventions I have been to utilized the assigned seating and it generally worked out quite well.
I'm new to this particular forum, but I completely agree. Besides having the TOTAL anxiety

over getting a ticket, this would probably be the next best thing. I have myself and another going, so finding two seats together may not be that bad of a thing. But for a larger group? Tickets are bought in sequential order anyways, otherwise they wouldn't be in ordered "groupings" of color blocks. I think to at least have the notion to put seats into play, even if there is a line each day (although we all know none of us really want to stand in lines!) to keep the seats we have and not have to worry about them may make this easier going. Like someone said, unless they want to switch. Many of the conventions I go to have assigned seats and badges are numbered for panels just for that reason. Just throwing my two cents in!

Like I said, I'm new, so that being said!