My idea of McMansion hell is how closely they build them together AND the placement of them.
For example, many of the big communities built here in Central Florida have your living room facing the ACs of your neighbors unit, and your living room windows facing into their bed room windows.
If your homes are less than 8ft apart, JUST BUILD TOWN HOMES...
But I don't really disagree for a lot of situations, especially without kids. I've always tended to prefer moderately rural or urban and not so much in-between.
They put every kind of shape, texture, and material all into one house, in one room.
This kind of maximalist design is trying to seem luxurious. But it ends up being overwrought, shocking to look at, and filled with unusable features like that weird fireplace in the 'dome sweet dome" house.
That's a failure of architecture, too; it's entirely possible to build houses near each other without that happening.
(Mind you, in general architects are unlikely to be involved in these, particularly where they're one-offs/customised).