The article's argument is based on a known-false assumption.

It assumes that people will automatically buy the next-highest fare bucket in order to avoid the horrors of Basic Economy, but the history of the airline business in the US over the past couple decades suggests that the vast majority of travelers will complain about how horrible the low-fare experience is, then book it anyway.

You missed the point—when airlines introduce Basic Economy fares, they don't drop the price, they instead drop services. So at best, you're paying the same for poorer service, otherwise you're paying more for the same service. Either way, the cost of those services is going up.

The article offered only one anecdote of a previous lowest fare price becoming the basic-economy fare price. Meanwhile, it presents as its main thesis that most people will spend more to not get basic economy, which is demonstrably false.

The thing is, it doesn't matter if people will spend more or not. Say you regularly purchase something, and pay $10/lb for it. And you usually buy a 6 pound package. So you spend $60.

And the one day you go into the store, and they tell you "We just introduced a new Basic Economy package!". It's still only $60, but now it's 5 pounds instead of 6. Or, for $12 more, you can upgrade to your previous 6 pound package.

May you pay more to upgrade, maybe you pay the same—but either way, what used to be $10/lb is now $12/lb. The price went up.

I think you're missing the fact that they were offering better service than the discount airlines but at the same price. It was the only way to compete when most people who travel infrequently purchase strictly on cheapest price. In effect they were offering a better service than people were paying for because they had to.

Now they are finally updating their seating and policy to be in-line with what the discount airlines offer. So they aren't charging more for economy. They're pricing it inline with the level of service you get, something they weren't able to do before.

You're still trying to generalize from a single anecdote provided in the article. That doesn't work out.