I disagree.
This statement assumes that "two Detroit pension funds" have enough votes to oust the board of directors or that the stock is structured in a way that they could ever get these votes, even with voting trusts or voting agreements with other shares. I can easily guess that Yahoo stock structured as such and if I am wrong, please correct me.
So, if I was managing a pension fund with languid Yahoo shares and not enough votes to do anything, my smartest and perhaps only move would be to sue. 62% ABOVE the actual market price of the stock? At that potential premium, if I did not sue, the pension fund might be coming after me as shirking my fiduciary duties. This does not mean I will win but its better than flailing around while the Yahoo board figures out a way -avoid- a merger and possibly prevent my fund from realizing 62% ABOVE market price on my sagging Yahoo shares.
So, from my perspective, it makes complete sense.