Should restaurants be concerned about stuff like whether the dishwasher is hot enough to actually sanitize the dishes?

Well thankfully when it comes to cellular life such as bacteria or viruses heat isn't the only factor that helps eliminate them, soapy detergents have a big role in killing them because essentially they stick to fats making them easy to remove and cellular membranes are composed of phospholipids by most part and those are very vulnerable to be destroyed by soap, thus poking holes in the membrane and killing the cell.