Ideally, the labor market is competitive. If a company tries to offload it's legal costs to its employees, they'll find work elsewhere, at least in aggregate. Ideally (again), shareholders do not have that option.

When a company goes under or significantly downsizes there will of course be impacts on employees. But equally, their competitors' employees may thrive.

I want to stress again that the alternative is basically lawlessness. If a company cannot be held to account merely because doing so might hurt employees, then it's in shareholder's interest to ensure the company disregards those laws whenever they get in the way of profits - which they can do by selecting boards and CEOs that are willing to take "risks" (and it seems quite unlikely that's ever likely to change). Those agents of a company might not even be in the same jurisdiction as the law, so trying to exclusively hold them to account seems like a pipe dream.

In any case, if laws try to very narrowly focus liability, you're also asking for games of musical chairs, and because it's so easy to create and destroy corporations, that's a game that will often lead to evaporation of any penalties.

Shareholders absolutely need to be held to account for the choices their companies make. Even limited liability is a protection with some problematic consequences; we definitely shouldn't make it even easier than it already is to shift burdens onto others or society at large than it already is.