It's either they lack in imagination/motivation to name and describe the piece in question, or what you suggest. I'm inclined to believe the latter, tbh.
This is because I remember coming across someone who was blatantly stealing art from others who had obviously put a lot into their work, from the skill in the art to the naming and even the descriptions put forward. But the one who stole them merely named them "Fantasy art" and the same went in their descriptions, too. The worst part is they were stupid enough for it to have all been done on this site. Stole from one person on here and put on their own account on here.
The fact people Steal art is a compliment in a way to the others work as its worth people wanting to take, but it's also a grave insult for the fact they worked so hard to just have it stolen and passed off as their own. Says a lot about the thief, in my eyes.