That doesn't strike me as a problem. Definitions are often highly abstract and counterintuitive, with much study required to understand at an intuitive level what motivates them. Rigour and intuition are often competing concerns, and I think definitions should favour the former. The definition of compactness in topology, or indeed just the definition of a topological space, are examples of this - at face value, they're bizarre. You have to muck around a fair bit to understand why they cut so brilliantly to the heart of the thing.