They were able to resist enshittification for a long time because they were actually one of the most profitable airlines and were able to keep their unique culture.
Then they had a flight meltdown, lost a bunch of money, and got targeted by activist investors.
You are thinking long term profitable, but most of the current "activist investors" barely think about short term profitability, and mostly from the perspective of their own profitability selling shares or running a short somewhere and "indirectly" helping their short by giving bad advice to a different company. They mostly read the quarterly reports and that mostly to look for "easy profits" Company A is making that they could pressure Company B to do for a quarter or two to bump stock prices before they sell again. Swoop in when a company has a bad quarter, pressure them to have "one good quarter", sell, rinse, repeat. (Makes them good money, makes most companies a race to the bottom to appease their whims as short-term investors.)
It's a good idea in theory if you can somehow force dividends to some long term vesting strategy to reward long term investors over short term investors.
It's a bad idea in historic practice, given the very origin of the turned out to be awful, something of the root of much short-term-ism and "activist investors" in the first place, "fiduciary duty to the shareholders" phrase was the awful Ford v. Dodge Brothers case where the Dodge Brothers were some of the earliest investors in Ford (as partners and parts dealers for Ford) and went to court to argue that record profits in a particular quarter should not be invested in long-term capital investment (a large new plant) and R&D as Ford was planning to do, but presented as a windfall of a large dividend to shareholders instead. The court agreed with the Dodge Brothers for, er, dodgy reasons, and the clear conflict-of-interest motive from hindsight of the Dodge Brothers "activist investing" in that moment was to notoriously use said dividend windfall to expand their efforts as a Ford competitor (produce more Dodge cars, if you haven't guessed) from Ford's own profits.
It's not a single court case that gets us to where we are today with short-term thinking in Wall Street, but that's such a weird foundational one.
They've also made some longer term strategic flops, like investment into Hawaii, which by its isolated long-haul nature is significantly different from the rest of their flights (usually short hauls that can maximize aircraft utilization per day)
Then they had a flight meltdown, lost a bunch of money, and got targeted by activist investors.