Changing laws regarding investors and companies (US)

I’m thinking about things like, in this thread posted a couple of years ago about Microsoft trying to buy out Yahoo and Yahoo saying no.
Although the official reason was that Yahoo wanted $37 a share and Microsoft was only offering $33, some other good reasons were given why it might be a bad idea, and yet as this post puts it:

It doesn’t matter what would happen to Yahoo after a buyout. If it would increase shareholder value then it must be done. Microsoft could buy it and things could go great. Or Yahoo could be like all the other companies Microsoft buys up and then puts out of business, but it seems like the fate of the employees doesn’t matter as long as the shareholders are happy. At least that’s the way it appears to me.