The easiest part - cut workforce to improve bottom line (and share prices, as management gets their own stock options), kill R&D.

Engineers* quit as part of their remuneration packages are stock options.

Overall perception and morale, hard to acquire new talents, etc.

Companies can and do leverage the capital provided by their stock value, so just there would be an influence (less value = less capital = less ability to make market moves), but beyond that, I think, as others had mentioned, it could have an outsize negative psychological affect on the workforce. Plus, it could cause a feedback loop of sorts, as other investors might look at the short and jump in on the chance that someone knows something they don't, causing it to further decline, causing a multiplication on the above issues.