Genuine answer: because it makes language less accurate and if you have to infer what the other person is trying to say (instead of what they are actually saying) that is just unnecessary energy wasted and it WILL create misunderstandings eventually. Disclaimer: I know this is about accurately using language, but as English is not my first language, this comment might not be entirely accurate itself, lol. But I am observing similar situations like the one this post is about in my first language (German) as well