But where would the former practice come from? Doesn't it imply that humans exist or used to exist, and that everybody thinks their way of doing things is/was somehow superior (and thus is appropriate for high society)? Or maybe (non-human) apes are highly regarded and everybody imitates them?
Why are wolves walking on their hind legs? Why can everyone speak a common language when their bodies aren't physically capable of making the same sounds?
No matter which line you choose to suspend your disbelief at, it's an arbitrary choice 🤷♂️
I've always thought the glasses would have long dispensing necks, like a speculum with just one blade. The glass is inserted into the muzzle, resting on top of the tongue, and the liquid flows into the back of the muzzle to simply enter the throat. Fancy wine glasses have small channels to allow minute amounts of the drink to pass through the dispensing neck to the tongue.