I am more concerned about someone stealing the entire truck than just the hitch.
But I really don't worry about either. I take reasonable precaution and pay my insurance.
If someone is going to climb into my truck and wrestle out the hitch they can have it, I can't imagine a pad lock stopping them if they are that determined.
Hitches don't have a great resale value. They are just too heavy and not that marketable. The resale market is very slim. In short there are many easier things to steal............like the whole truck.
There are a lot of things in life to worry about,however my hitch is not one of them!