I've looked at the eligibility criteria and to actually benefit from the policy you have to be in really bad shape in terms of not being able to perform the activities of daily living. We're talking not being able to make a bowel movement independently. Most old folks are not and will not be in that situation, and thankfully so.
My view is that it's best to self-insure by investing. In addition to standard retirement money, have a separate bucket set aside for elder care. You likely won't need the money until your 70s or 80s so it should be 100% stocks and no bonds.