Unreserved seating makes theatre more inclusive.
There are so many shows out there where I wonder how anybody can actually afford the top band seats. Worse still – premium seats. If unreserved seating was used, then all seats would be the same price. In theory, then, the issue of only a very fortunate few being able to afford the 'best' seats would be put to rest. Or would it? It could just as easily be the case that unreserved seating would lead to none of the show's tickets being affordable, which would be even worse than only some seats being affordable.
People who book months in advance should get the best seats.
If you're desperate see a show, and book months in advance, it is reasonable to want to be able to have your pick of seats; it is one of the perks of early-booking. If unreserved seating was used, then somebody could book 30 minutes before the start of the show, and still get better seats that you. It doesn't seem quite fair.
People who arrive early to the theatre should get the best seats.
There is nothing worse than latecomers stumbling around a dark theatre trying to find their seats. Surely somebody who gets to the theatre before the house even opens should be able to chose their seat before somebody who may not even get to the theatre on time.
There are less 'wasted seats' with unreserved seating.
I have been to several shows where, during the interval, there has been some drastic reshuffling of where people are sitting. Mainly, this seems to happen when a group of people don't show up to the theatre, and leave a whole row of great seats unused. With unreserved seating, like the current production of Guys and Dolls the best seats are always going to be used first.That said, a major risk with unreserved seating is that groups of people will leave single seats between themwhen they sit down. It is unlikely that these seats will be filled, which can mean that just as many great seats are 'wasted' as if reserved seating is used and there are some no-shows.
All in all, I prefer the traditional approach that you find for shows like Phantom of the Opera and The Book of Mormon. Whilst there are some theatres that it just can't work for, most theatres can – and, in my opinion, should – stick to the ever-reliable reserved seating.