Example: "arreglo". Why would you call an array that way?
Learning a programming language is already hard enough (especially the first one) to add another axis to the process, and you'll get much less out of the experience if you are limited to a "vainilla" universe.
The terminology is well established and standardized in english, so if someone says things like bus, heap/stack allocation, driver, or even simple random things like timeout, tracker, to trim a string, to wrap an error, etc. everyone knows what you mean but when people write their docs in spanish and make up their own terms (let alone the mental effort required to translate every term), you can quite easily end up with a huge mess.
Por favor, programad en inglés y usando los términos conocidos y si tenéis un equipo a cargo forzad a hacerlo así, os lo agradecerán en el futuro!
I have a theory that the frequency of the use of those translations (arreglo, aplicativo) in a workplace is directly proportional to the amount of bureaucracy in it.
In fact, what's popular now is to do just the opposite: linters and formatters which force the same coding style for everyone, which is way easier to implement for all the different languages and way more reliable.
And as far as the language itself is concerned, I'd say that it is a bad idea as well because of context switching, translating what you type into other languages (which is not a trivial task for both machines and humans) and because, as I said above, you still need a good english proficiency level if you want to be a good developer, so it makes sense to prepare your students for the real world by teaching programming in english and getting used to it.
I'm fine with programming in english, this only complicate things for everyone involved. Imagine if every popular language out there had their own adaptations or even their own programming languages.
Also, you must know english for coding. There is no way you can be a good developer without a good english knowledge - docs, specs, protocols, guides, tools, books, remote jobs with international teams... everything is in english.