Because it leads to confusion.

Example: Is the proprietor of a bar the person running it or the landlord who owns the building?

Actually, it is generally understood that the owner/proprietor of a bar is the business owner (aka license owner) -- and that this in general is not the same person who owns the bricks.

A more clearcut case of semantic confusion I can see a crappy AI creating out of the blue would be:

"My proprietor said if I didn't pay the rent soon she was gonna ..."

Which clearly has a very different (and basically nonsensical) meaning than a the more natural formulation using the now thankfully forbidden L-word.

Agreed, I was just trying give an example of why using proprietor would create confusion.

Right -- the "bar's landlord" is in general not it's proprietor.

Well it's funny you should say that...

https://www.oxfordlearnersdictionaries.com/definition/englis...

"Its". Me of all people.

Why not use Landlord, a word everyone understands?

Here's the definition of landlord I see

> A landlord is the owner of a house, apartment, condominium, land, or real estate which is rented or leased to an individual or business

How is that different from "property owner"? The difference is that to you, a native English speaker, landlord is a word you're familiar with. To others, it's a whole new word they need to learn, whereas property-owner is self-descriptive. It's like using good variable names in your code, you don't need to look up the definition of every word when you use re-use words that are common.

> How is that different from "property owner"?

They mean different things: one is a subset of the other. A person who owns their own home that they live in is a property owner, but not a landlord.

> that they live in

Well that's new to me, because I absolutely do not get that from the term "property owner". For example, if I have a place I own that my brother lives in, and someone asks my brother "who is the property owner", he would definitely answer me. I own that property. How does the term property owner say anything about where the person lives in?

Because it promotes wrong and harmful thinking. And must therefore be extinguished.

Perhaps it's a very specific answer, but I write in simple English, since many of my readers are not native speakers. I stick to words people are likely to understand.

Our local immigration office recently picked a newer, better name, but since no one uses it, I'm sticking to the old one.

Another one is expat vs immigrant. I favor immigrant, but I can't rename expat insurance to immigrant insurance. The latter does not exist.

I use the gender-neutral "they" across the website, but sometimes "he" would be a lot clearer when replacing a singular noun like "the landlord".

Sometimes the common word is the right word to use. When in doubt, I refer to Google Trends.

If you say "I paid my proprietor this month", nobody will understand what you mean. It's simply a different word with a different definition.