Not sure why but it is delicious to me. The vinegar is another dimension to the hummus. The mouthfeel, flavor nuances on the tongue, and balance makes it so damn tasty to me.
The chili sauce is only on the top so it is not that much but just enough to add another level of flavor.
Try the sesame oils infused with chile. Any Asian market as well as well-stocked grocery stores will have it. Usually in tiny bottles, but sometimes found in larger ~6oz bottles too. Read the ingredients though - soybean oil might be mixed in. It may or may not be to your liking