Why would a language lack a T-V distinction, but with a pronoun system that is the opposite of English?

Question

In English, you is used both in the second-person singular and in the second-person plural (thou is now only used in some old proverbs and old expressions).

At the opposite, French (my native language) has a T-V distinction: tu is always used when addressing to only one person, but vous is often used when addressing to multiple people; however, sometimes, vous is used for only one person despite being always syntactically plural. When addressing to only one person, vous is reserved for strangers, or people older than oneself, or authority figures.

In my world (in the sense of a fictional universe I want to create), in the most spoken language used by therianthropes (their scientific name is Homo pilosus, so they are humans, just not Homo sapiens) (Homo pilosus means "hairy human"), Di is exclusively used in the second-person singular (even when addressing to a monarch, a president, a stranger, a deity, an elder, etc.) and Wos is exclusively used in the second-person plural (in their language, pronouns are always capitalised) (if you ask me, in the most spoken language used by therianthropes, the w is pronounced like the English w as in "world").

So, I wonder why would a language have a second-person pronoun system opposite to English.

Answer 1

I agree with most of No Name's answer, but I disagree with "this is a significant departure from human psychology".

Look at this map (via linguisticmaps.tumblr.com) showing which languages in the world have a T-V distinction—that is, a formality distinction in the second-person pronouns.

A T-V distinction is common in Europe, and more elaborate formality systems are more prominent in Asia, but large parts of the world (and in fact most of the world's languages) don't have such a distinction. In Swahili, for example, a single person is always wewe and a group of people is always ninyi (or nyinyi depending on dialect), whether you're showing respect or not. Instead, respect can be shown in other ways, such as adding a title like bwana (the equivalent of English "you" vs "you, sir"). Even in Europe, in Classical Latin the plural pronoun vōs (presumably the source of your Wos) was primarily used for groups of people; the T-V distinction was a later development in Romance.

So you don't need any justification at all for your language to work that way; it's how most languages on earth already work.

Answer 2

You don't really need a reason to not implement a T-V distinction. Just because your native language does, doesn't mean every language does.

But if you insist: In German, "du" (the T pronoun) is used to address God, suggesting that they (or rather, the people in charge of these things want them to) think of God as more a friend than a ruler. Perhaps your therianthropes have a populist leader who insists he's "just one of the guys", so pluralis majestatis (i.e., the royal we) never got off the ground. No royal we, no royal you; no royal you, no T-V distinction.

Of course, this is a significant departure from human psychology, as plural=power is an old, old cheat code, and we love power and flaunting it. But you've already stated that these people are Homo, but not Homo sapiens. Different species within a genus can have significant psychological differences, such as that between Pan troglodytes (the chimpanzee) and Pan paniscus (the bonobo). All of this, however, is worldbuilding - I'd suggest any follow-ups go there.