Salam Brothers and sisters,
Allah made people using different colours of soil from all four corners of the earth and Prophet Adam was taught many different languages hence why we all use different words to describe the same thing.
Lets not make a big thing about the word "Namaz" as from the moment you read the original post you understood the word meant "Prayer" or "Salah".
It is not about correcting people its about the languages that they have grown up knowing and speaking, remember not many Muslims can speak Arabic.
Salam alai kum