Read through that sticky about Dometic Recall (and probably the Norcold one) and you'll see they felt no obligation to replace the faulty cooling units, only to try and keep fire from spreading. Band-Aid also hides a Compound Fracture.
You can get a New or Reman or Modified Cooling Unit and many are happy with the results of a DIY install. Having a tech install one probably approaches the cost of a new fridge.
There IS a condition where changing only the Cooling Unit could make sense. In some RVs, the Fridge won't readily come out, since it was in place before Walls went on, Windows went in, etc. Cooling Unit CAN be changed by pulling the fridge and work on it inside the coach.