@WisherWood
It simply looks like spite directed at people who don't struggle socially.
This thread is starting to remind me of the expression that if all you've ever known is privilege, equality starts to look like oppression. From the OP Person A is pretty unsociable. She gets on the bus and looks forward to time alone to sit and think/daydream during her 1 hour journey. That's the OP herself describing her own behaviour as 'unsociable'. That's how ingrained the prejudice against introverts is, that something that is in fact perfectly normal and valid becomes 'anti-social'.
As an introvert, I have no problem making friends. I'm happy socialising. I'm not socially awkward. In fact, friends will push me forward as the person who doesn't mind going first, speaking first, entering a public space they're worried about being in. In your own attempts to stand up for extroverts, you imply that introverts all 'struggle socially'. See how embedded your opinions are?
And yet I do not, as an introvert, struggle socially. That's not what the definition of an introvert is. To recharge my batteries I require down time away from people. That's it. I'll give public addresses to hundreds of people. I'll go to parties. I'll chair meetings. And then I want to go home and not chat to people. That's not 'struggling socially'. So if you're going to get your arse in your hand about the way extroverts are being described on MN, maybe have a closer look at your own prejudices first.
What we need to recognise more is the extent to which needing to be around people to recharge is normalised, whereas needing downtime is stigmatised. Needing downtime does not make you socially awkward, or inept. If you struggle, it's because the world is organised for temperaments other than yours, not because there's something innately wrong with you.
I've never suggested introverts struggle socially
I agree that this is an inaccurate view, based on a misunderstanding of introversion and extroversion. But it is this view which predominates on here the people who, by and large, self-identify as introverts, explicitly say that that they are socially awkward/reluctant/struggle with friendships, or alternatively, don't have any friends by choice. This is not MY prejudice, or my misunderstanding, it is the prejudice and misunderstanding of the majority of Mners who identify as introverts.
Like you, I am a social, socially-confident introvert. Like you, I give lectures to hundreds of people at a time, chair meetings, have lots of friends who make my life a better place. You would have no idea whether I was an extrovert or an introvert from my social presentation, The difference, as you say, is in the way you recharge. I need significant solitude to balance.
I don't think that needing downtime to recharge is at all stigmatised, actually. I think the issue is that people, including those who believe themselves to be introverts, rightly or wrongly, misunderstand what introversion is, and confuse it with social awkwardness. That misunderstanding is frequently seen on here, on a forum that seems to have an unusually large number of people who struggle with friendships, regard the school run with fear and horror, can't function in group situations or one-on-ones, or who claim they don't want friendships at all, because they're 'too much drama'. Those people identify as introverts, but they are likely to be a mixture.
My point in relation to the encounter between A and B on the bus is that we have no idea whether Person B is an introvert or an extrovert. There are introverts who will nervously babble in this kind of situation (my mother is one), or introverts who are thoroughly 'recharged' from a period of solitude, and who feel like being sociable, regardless of the situation, just as there are extroverts who will be unable to understand someone's desire for solitude. All we know about B is that she did not read social cues.
And my general point is that we should not be stigmatising either introverts or extroverts. Poor social skills and tactlessness are a different matter.