locusts
They're not "activist investors", they're locusts.
It's a playbook at least decades old, probably much much older:
1) get enough control over a company (shares held, board membership, paid-for executives, etc.) to direct and enact policy
2) reduce costs by any means -- e.g. cut bonuses, benefits, and salaries; hiring freeze, layoffs, painful reorgs, restructures and sell-offs as employee resignation incentives; slash budgets and spending, anything that might allow money out of the company coffers; none of it is sustainable but merely contributes to ....
3) sort-term spike in share price
At that point the locust investors declare "job well done", sell and cash out, leaving behind a stripped and shattered husk and usually a demoralized, probably damaged and much smaller workforce, and in all likelihood a company which isn't a going concern much longer. Any executives left behind take their pre-planned golden parachutes, "spend some time with family", eventually score Board of Director seats elsewhere, maybe a consultancy with an activist investor group, and the cycle repeats.