Java in a large way has been eclipsed by most other languages, and developers kind of have a way of making fun of old technologies, like a lot of the same jokes are made about PHP which is still very popular but outdated. In reality Java is also still incredibly popular and knowing it is certainly a benefit. It's just a collective joke.
Absolutely my first job was fast food, and I had no clue the level of entitlement of some people. Some people treat fast food employees like they're not even people.