I had the same reaction as the OP. I’m not a data scientist by trade or title, but I would personally be a little offended. If you designed the Porsche 911, would you not be offended by the shade tree mechanic who simply knows how to change the oil calling himself a Porsche designer/engineer?
There are people making applications based on LLMs. You may quibble with the term LLM Developer, but to sneer or roll your eyes at it as if it were prima facie inaccurate or laughable is unjustified.