Because they have no interest in understanding what any of what they’re saying actually means. In my experience it really usually is as simple as that. That’s why they also don’t care it’s wrong - „you know what I mean!“
What I actually find even worse is people from the industry who do know better saying things wrong in a misguided and completely unnecessary try to „shorten things“ - I.e. saying kilowatt instead of kilowatthours. Bloody morons. Similar: going „back in two-15“ instead of twenty-15. what the fuck?
I can’t read this without mentioning my all-time “favourite”: “There’s no chemistry in this product.” First of all, the moron in question usually* meant “artificial chemical additives” and second, how THE FUCK can you be this stupid and run any part of any business?!?
*But not always. Many years ago, I actually heard some idiot touting her apple juice with the words “free of preservatives, we don’t add anything like e.g. ascorbic acid”.