The NYT had an interesting article on failure.
Here is my basic response. I hope to have time to elaborate on this later. There are many kinds of failure in many arenas of life. Some are terminal (of course, in one sense, success is ultimately terminal too since we all die, but I assume we’re talking about more immediate consequences) and should be avoided.
Pedagogically, I have found with my students that pushing them hard enough that even the best fail is useful and usually appreciated provided I also provide a route by which they can learn to come back with success. That is what I (among others) call “authentic challenges.” Certainly, in my life at least I have learned more from failure than success though, of course, the success is more enjoyable…