ummm ... I wouldn't put it that way "to the insecure or uneasy buyer" its a "perk", a "bonus", from the seller, so why not?
Quite honestly, if you dont get that warranty from the seller now a days, you had a bad real estate agent or if you bought on your own, you didnt do a very good job because its just a insignificant cost to the seller.
As far as worthless, that goes for any insurance, insurance is a product that companies make money on, its why it is called an insurance company and they make huge profits on whatever they insure.
So anyway, to a buyer, who just buys a house, its kind of a cool feeling if something is wrong when they move in chances are it is covered, IF they made sure to get what is called the "premium level protection"
Otherwise just the basics are covered and that is still a good feeling because it covers the essentials, heat/air ect.
I never had one but I moved a lot of real estate in my lifetime and I see the basic value in them, my son did have one (recently in the last five years) provided by the seller and needed some repairs the first year, like a new water heater that was fully covered except for the 50 or $100 deductible. He also had other small things fixed over that year.
Not a big deal but if you dont get a paid home warranty from the seller, then, in my mind, you didnt do a good job (or your attorney or real estate agent) in putting the deal together. The cost is nothing to the buyer and in essence the seller is warrantying that the homes basic systems and more) are in good shape. To me, its just good business sense.