why do enterprise apps that cost millions have worse usability than word 97 still?

1) enterprises judge quality based upon how expensive the solution is compared with competitors, at least partially anyway.

2) they get used to a UI and look at new features or layout options with fear, that normal people would consider to be awesome.

Design by committee, company employees that give the wrong direction to designers and developers due to ego, confusion, misplaced priorities.

Just here to bring the cynicism.

And some have non-existent documentation.

One of the biggest factors is trying to fit every possible feature into a single system, when not all those features fit whatever UI model they've settled on. Trying to design a system that is all things to all men will always lead to inconsistencies and quirkiness.

Also, at times you can see very clear lines between parts developed by different sub-teams. It's difficult on systems of that size to have proper oversight of all pieces.

And as someone has already said, UX changes between versions can't always be as dramatic as best practice might suggest. Customers may have spent a lot training users and have reasonably efficient processes even based on bad usability. Good, bad or indifferent, any UX can be learned over time.

But I totally agree with the question, it does seem bizarre how bad some of them are.