Tenure is a benefit which has an "opportunity cost". For me, it has a specific value. It is calculated as part of salary in determining whether a job is beneficial.
Also, being in academia has little to do with teaching. The game is scholarly research. Maybe not at this small Texas college, but at most medium to large Universities, it is THE determining factor.
If job performace were tied only to teaching, I wouldn't concern myself at all with it. Teaching is easy.
As far as potentially having to move if you get laid off,
There aren't "lay offs" in academia as such. The department, for example, could decide that they will go into an entirely different field of research because it's "hot" now. They could fire virtually the whole faculty (if no tenure) and start anew.
This would have nothing whatsoever to do with job performance or self-induced insecurities. Now, if a University wanted to have such a possibility exist, that's fine, but they're going to have to pay me a lot more to get myself into such a situation.