A game engine is sort of just a UI toolkit for interacting with 3d objects. If you want a 3d model you can interact with, you call that a game engine. Should they invent something new because they dislike the word "game"?

Worked for a shop that had the hardest time grasping this. We had to tell them UE4 was a "3D Rendering Engine" because they couldn't get over the term "game engine" in planning meetings...