It came years late and was laughably buggy. And 6 months later it's still laughably buggy.
There are plenty of pre-written tests used by the other browser vendors that would have shown them it's shit before they released it. Or they could have just tried using some websites that use IndexedDB and noticed that basically all of them broke in their browser.
That means malice, horrible incompetence, or horrible management. I doubt it's incompetence. It could be horrible management. But it's just so bad that you can't help but think about malice...
That rarely means malice. That usually means overstretched engineers.