What's sold under that name in North America is revolting. All the main brands are, just a few more recent (and expensive) gourmet brands are OK, but they're not worth it at the price, not when it's so easy to make at home.

The real thing is awesome, but a great deal of people who've known only the commercial stuff hate mayo passionately (and for good reasons).

It's much the same with "american" mustard that hardly includes any mustard, and ketchup like Heinz's. Vile, vile stuff.

Mayonnaise is only remotely more revolting (unless you include mayo-style sauces like Miracle Whip for which its makers would deserve to be accused of culinary terrorism if there was any justice in this world).

It's hard to believe anyone could have improved on the horror of British condiments, but North America did it, and transformed French classics like béchamel or mayonnaise the same way.