"Are a company's shareholders really more important than its employees?"

Shareholders in this sense actually represent financial responsibility.

One could argue that Yahoo! has been hurting it's employees by failing it's shareholders (financial obligations). As a result, massive layoffs will be required, whereas if Yahoo! had maintained it's health, it's numbers would have grown/shrank organically.

In this sense, the Alibaba money only delayed, and made worse the correction to Yahoo!'s underlying business model.