I quite like Barbershop, as an outsider; I've never had the musicality to join in, or the inclination to go to the trouble to of learning to sing harmonies. (Thinks, is this why my 'career' has been so limited?)
I liked it enough to want to 'expose' a very English folk audience to the genre by booking 'The Reading Barbershop Quartet' to appear at the Caversham Charity Folk Festival a few (10?) years ago. They went down a bomb at the concert and earned themselves a lot of friends by being seen to be busking with the general crowd milling around in the carpark/craft stall area later on.
In general the costumes and exagerated gestures/choreography make me cringe, but I admire the 'tight' presentation when it's there. But then that is a quality that marks 'good' performers in any genre, difficult to define but instantly recognisable when it exists. Examples of this quality in the folk world that spring to mind are William Pint and Felicity Dale and 'Artisan' RIP.

All the best
BobH