The author.
Unfortunately due to extrovert (and pretend-extrovert) majority in the world there's always an undertone of "this is the right way and everyone else is weird" lingering in the society.
If the majority were introvert we would land up with people bragging on their resume about their thoughtful quiet nature rather than "oh so outgoing and BUBBLY!!".
As Tycho said, yes if I don't speak to you don't be so arrogant as to attribute that to my shyness maybe I just don't give a fuck about you. Not saying that that's always the case, but hey leave some room for that possibility.
How about this, what if every time an extroverted talked loudly and excitedly to me I just turn around and tell everyone "Oh don't mind him he's just really desperate and lonely and just wants some attention.".
See? Instead of assuming that that's your nature I can assume that is your flaw and you are unable to shut up.
That's exactly what extroverts do to introverts when they attribute being quiet to being shy or having social anxiety or being "socially awkward" and all these labels.
That said, it's reasonable to say I tend not to like the banal banter of drunk people. It's probably true that the overall drinking culture is banal but banal is an escape for a few hours for a lot of people. You don't have to join them on that one.
I don't think there's anything suspect about being bored by many conversations. Maybe lots of people are boring to him. Not everyone shares interests.
Also, I don't need to "recharge" by retreating to solitude, I just find lots of partying, drinking type situations incredible banal and would rather do something else. This is just like getting impatient with any other activity, like watching the shopping channel.
Of course usually I don't say this to people. That would just be rude.