On the surface, because they're told to push it.

Further down, so that developers are used to train the AI that would replace both developers and managers.

It's a situation like this:

Mgr: Go dig a six-foot-deep rectangular hole.

Eng: What should the rectangle's dimensions be?

Mgr: How tall and wide are you?

Because management already spent 50 billion dollars on these magic beans and now they really really really need them to work.

To validate the huge investment in openai - otherwise the leadership would appear to have overpaid and overplayed.

There are other options to do just that instead of ruining developers' life and hence drastically lowering the performance of teams.

In companies this large and old, the answer most often is a 'no'. The under-performers can now be justifiable laid off with under-performers worthy severance, till morale improves.

Money.

The stock price isn't going to go up on its own. Even when MS was massively profitable in the 2000s, the stock used to be stuck in the $30-$40 range because Wall St didn't think it was "innovating" fast enough.

At Microsoft, because they sell that stuff and it would be really bad for their image if they insisted they work better by not using it.

(Or, rather, I have no idea how this compares with the image of they actually not delivering because they use it. But that's a next quarter problem.)

At every other place where management is strongly pushing it, I honestly have no idea. It makes zero sense for management to do that everywhere, yet management is doing that everywhere.