It's clear by now that these layoffs aren't targeting low performers. They're not targeting any individual. They are an accounting exercise with selection based on meeting a formula. The suggestion in some quarters is that there's a kind of collective hysteria driving the layoffs amongst tech companies. Incorrect. The one thing all these companies have in common is that they all have the same pool of institutional shareholder.
The layoffs are not about saving money, they are about being seen to save money.
The institutional shareholders have demanded this be done, and the boards have complied. The big layoffs - Google, Amazon, MS, etc - are largely pointless and don't make any meaningful savings. And let's not do the "thinning of the herd" bullshit, please.
Why have the institutional investors demanded this? 1) because they've become accustomed to make obscene amounts of money and want to continue making obscene amounts of money even when things are slowing down, and they (wrongly) believe laying people off is the way to do this 2) because they can. They hold the real power.
Apple have largely avoided doing layoffs because his 40% paycut has soothed the baying suits, and Tim Cook is in a powerful position anyway. Most other CEOs, not so much...