Theology often is best when states in a plain way. I tend to be suspicious especially in debate when a side moves their theology into a set of language which is difficult to determine without an advanced theology degree.
Maybe the person is simply a poor communicator and cannot communicate their ideas in a way which is simple to understand. This is often the case but complex ideas can be stated with clarity in common language.
So the goal of this communicator should be to better understand their subject so they can communicate with greater clarity. It is a sign at times that one is at the edge of ones knowledge if we cannot explain complicated concepts in a way which is understandable.
Often though the retreat into complex rhetoric singles and uncomfortableness with the debate. Sometimes you will see someone without formal training make a point which is quite condemning in the best sense to a position and then the more learned person moves the conversation into safer ground where what he is being said cannot be understood.
You see the point is that the goal is truth and understanding, not winning arguments. If one cannot win an argument without trying to befuddle others with terminology and tricks then one should not attempt to win.
Often the great complexity of debates is an attempt to move away from the truth. Even if this is not the case we should seek plainness to speech so everyone can understand and judge for themselves.
The truth shines in the light. Vagueness, confusion, and speaking to not be understood are not in general virtues.
Sometimes there are times for words which are difficult to understand. You see Jesus with his parables often spoke things which are difficult to understand.
But in another sense they are very plain. You see it is the spiritual truth which is very difficult. There is not difficult language used to obscure the truth, it is simply the saying which are difficult.
The sayings are obscured in a sense to force people to see by faith. Sometimes we can only learn things for ourselves and parables offer that chance.