I think the requirement for whole life is less than the 1 million on each spouse after you take into consideration, future value of pensions, social security, and the whole life policies purchased, not to mention any savings that could be tapped. Rather than purchasing the $150 or $200 dollar a day coverage LTC with inflation adjustement, that may be realistically needed to cover LTC costs in the future, whole life policies along with other sources of income can be a way of reducing the necessary amount of LTC coverage. Many people (including myself) balk at LTCI because of the cost and the very real possibility that it may never be needed. In my case, If a reduced amount of LTCI can cover a potential "gap" in my ability to self insure, then it may very well be worth it.
Why is that a concern, at all? Insurance underwriting is predicated, among other things, on the very real possibility that many will never really put in claims for coverage, and the insured is always at risk that the policy may never be needed! LTCi cost is another thing, all together. The way I look at things, my cost for Term Insurance plus LTCi coverage might be cheaper than the cost for whole life insurance plus whatever cost one might have for disability insurance coverage, if you're still employed like me and use that as part of your support base for disabling events. And I might not have to touch any other assets.
I can self-insure, myself, but I think it's cheaper for me to purchase LTCi now as LTCi also covers me for a major disabling accident or event between now and retirement, and I do want to leave something left over in my estate.