Hear hear, it's simple etiquette
You don't need a reason to send a bottle of wine back, but gentlefolk only do it when it is corked - and then as you point out there is no need for a great ceremony, although it's quite acceptable to give the glass a good nose before tasting, and swishing the wine around does release the aroma; granted most people have a good enough sense of smell for this not to be absolutely necessary.
(lost, Fri 2 May 2008, 12:08, Reply)