MC offers primary rental car coverage domestically?

I thought both cards offer primary rental car coverage overseas and secondary domestically.

In fact Visa offers BETTER rental car coverage overseas because it covers Australia/NZ and Italy - those are countries required mandatory minimum LDW to be purchased, but Visa covers the excess (deductible) while both AMEX and MC simply exclude these countries from their coverage.

The better excuse would be, there are times hotel chains provide promotions that requires a MC being used in order to earn the free night. Therefore one needs a MC.

And as others point out, Sam's Club. (in the same vein as Costco only takes AMEX, any AMEX.) You use Sam's Club a lot and dont want to give up a great point earning opp.