They did if you wanted to play multiplayer which was a key element of their appeal.
$360 in 2019 ain't far off $310 in 2006, nowadays people casually buy $800 phones/tablets despite already having one that works fine.
But we'll probably just have to agree to disagree here.
... required means required. Mandatory. I can assure you I played and enjoyed all of those games, except Just Dance, by myself at times with a single Wiimote. If you want to amend your statement that's fine. But as you stated it, it was flat out wrong. We're not going to agree to disagree. You are factually wrong.
If you take it at straight up inflation, then 290 (seriously nobody wanted to play Wii Boxing with two people, and none of those other games required a nunchuck) is actually pretty much 360 even. But, people just don't look at gaming or pricing that way. If next year's Madden launched at 78.82, people wouldn't say "oh well due to inflation since 2005, that's a fair price". They would bitch about how expensive it is. Which is why game prices have increased in other sneakier ways.
Sure people will casually buy a phone for 800 dollars. But that's a phone. Different market. Or do you think people would buy an 800 dollar PS5?