It's quite a simple story, wall street likes companies that make profits - and by that I mean that they receive more in revenue than they spend. Now there's really a few ways of making more profits.

You can invest (spend more) and hope that that investment yields more revenue down the line. This is bad. Wall street doesn't like this, because you're definitely making less profits now because you're investing money you could've given back in profits, you might make more in the future - but no guarantee. Risky! Wall street hates this!

You can raise margins. This can be good. As long as demand is fairly inelastic this will pretty directly translate into profits. But you can only do this for so long, by definition you just always want to do this until you can't any more, so you've probably already pulled this lever as much as you can.

You can cut costs. This is good. Wall street likes this. You definitely get more profits right now. It could impact your ongoing growth, but that's just maybe! You can be more efficient right? And even if it does impact your future growth that's not going to show up for years. So right now, you're more valuable!