One of greatest successes at the University of Oregon was the development of the zebrafish model organism. It is now considered one of the best systems for studying many aspects of development and disease, and Oregon gets a large amount of cachet for being the source of it. Interestingly, George Streisinger took many years to make the system work, and was considered by any outside metrics to be unproductive during that time. He would have been first on the chopping block if his employment was in the hands of a bean-counting Dean and he did not have tenure to protect him.

Now, how to discern the unproductive from the temporarily unproductive future game-changers and protect only the latter? That I don't know. Maybe protecting game-changers is too much to ask of a university in dire financial straits and too much to ask of students in debt. But I think many people think of tenure as a way to protect just the political faculty; it affects the sciences as well.