Why would any institution make a deal like this?Does anyone really think that the quality of efforts to teach people about the law or how to be lawyers would fall? Exactly how would this work? The good professors would be draw away into practice and replaced by bad ones. Two problems here. Look around you. How many of the people in law teaching could and would leave for a job in practice? Do you really think there are not plenty of competent people willing to fill their positions? And, what's tenure to them. They do not have it and likely never will.
Would eliminating tenure change scholarship? When is the last time a law professor said anything controversial enough to engender widespread complaints? Now stack them up against those who will never say anything at all. Many of them have First Amendment protections anyway. Although they rarely need protection from complainers outside their schools (And please don't say they are so few attacks on professors because would be attackers know tenure exists.), it may be that they need protection from within the law school. What sort of people would need this protection other that whistle-blowers? The only ones I can think of are those who toil away on long term projects that are risky in that they may or may not result in "findings" worthy of publication. As it turns out, though, this kind of scholarship -- the kind that involves actually testing ideas and taking on tough projects is already rare. I am not sure it would be much worse as people with tenure clamor to rack up numbers no matter what substance is behind the numbers and administrators encourage and reward this behavior in part to puff up decanal glossies. Plus, remember tenure also protects those who do not even play the game at either level.
I am happy to have tenure but, as an institution hasn't it failed?