It's repair insurance and all insurance policies are a waste of money until you have a major disaster and need to make a claim. Some people will recover all their premium cost and more, but most will not.
The premiums on a 13 year old (2008) coach are going to be quite high, so think long and hard about your level of comfort and your ability to cover a fairly large unexpected repair, say $1000 or more. If you have to rely on RV dealer shops for every little repair, you can quickly run up some big repair bills, but even a little DIY skill can dramatically reduce those. And contrary to the ESC sales guys story, air conditioners, fridges and engines don't suffer major failures all the time.