Nobody said it isn't debt. The difference is that it is debt that makes sense: you can't realistically buy land without it, and houses tend to appreciate so the interest costs are less of a problem - they just represent the time value of money.

Most other debts people incur personally are to buy things they could save for, which go down in value. Like cars.

That’s the out. I’ve seen many people explain what their debts are and don’t think of their mortgage as one.

It's not a weird cognitive out, there are major differences, legal and financial between say credit card debt and a mortgage on a house.