Everyone's experience is different. I've had trouble with rodents eating cables before. That's why I suggested the conduit and a way to pull extra cables in.Never had a problem buried like that on my Florida property for 22 yrs. Also here in Ohio, going on 3 1/2 yrs no underground problems. The coax chewing rodents around here are squirrels who favor aerial lines.
We all do whatever works for us. If I have a recipe that is a success, I am hard pressed to change it based on someone else's advice. But, I will file it away in my mental file cabinet for future reference, if needed
Like you suggested....We all do what works for us!