What exactly do you want though?
The CEO to not have gotten a bonus? You can argue about the morals of it, that's fine. But if you're saying it shouldn't even be legal then you're saying the government should tell people what they can and can't do with their own money. That's even more unfair IMO. If the company wants to give him that money then they should have every right to do so.
The people shouldn't have been fired? So you think companies should be forced to employ and pay people that they don't want or need? That too is much more unfair as far as I'm concerned. If I had a house with a garden and employed a gardener to tend to it but then moved to a new house with no garden why should I continue to pay the gardener? That would be ridiculous.
That's also an apt comparison since Activision Blizzard are saying the layoffs are due to a transition to more digital distribution and events rather than physical stuff and live events. If they're not doing those things anymore then why should they still pay people to stand around and do nothing?
Besides, a lot of the layoffs are in Europe, and like you said there are employment laws for a reason so they'll probably be getting a big final paycheque that will help tide them over while they find a new job, plus Europe has plenty of welfare systems in place too so even if they struggle to find a new job for awhile it still may not be an issue.
A fairer system, that's all I'm saying for now
We are not going to solve this in this forum, the 'how' should be left up to the experts
But the first step is admitting we have a societal problem, by letting the tax payer cover all the employer unemployment expenses for a failed business whilst the CEO walks away with incredibly large bonus for failing, just means it was the tax payer that ultimately subsidised those bonus's to those rich individuals, doesn't seem fair and equitable, so lets find a way to change it, I don't know how, be we should try and not just see it as normal and do nothing or say nothing