Because all people all over the world for all of time have resisted learning how to spell and pronounce the words that other people use. Part of that is because after a certain age (around 25) you lose the ability to make certain sounds that you haven't already learned (hence why many speakers of Asian languages mix 'r' and 'l', and why English speakers can't pronounce a particular kind of 'r'/'h mix that exists in French). Part of it is a resistance to learning about other people. And part of it is just how language works anyway.
It's because everyone wants to fit names and nomenclature into their own language's system of naming. It'd be an unending fucking hassle to learn what every group of people call the place where they live - and that's even if you can get all of those people living in that region to agree on what the region even IS.
I mean, did you ever consider that maybe not all the countries we call '-land' use a language with suffixes on their place names? That assumes they USE suffixes, and that they use suffixes for PLACES, and that the particular suffix they use for a region is '-land'. Poland, Swaziland, Finland, Iceland, Thailand. I guarantee you few to none of the people in these places use the suffix '-land' for any region, let alone their own.
But ok, let's say you want to throw this all away. Let's just call regions what the people who live there call it. Let's go to the effort of learning what everyone else calls every other place ever. (You can probably already see the problem you're about to hit.)
What is a 'region'? A single infinitesimally small point? The whole world? Something in between? How do you define that something? By what the people living there agree is the region/place? What if different people living there don't agree on what area even IS the region (see: Israel/Palestine),or what it should be called?
And so on. And it's not that people really sit down and think about all of these complexities, but that any particular word in any particularly language is an approximation of an approximation. If you're curious what I mean, go ahead and google Ferdinand de Saussure.
And it's really good and important to learn what other people call their home. But it's basically impossible to ask a while group of people to take on that effort for every other group of people.