exams are like french fries

To continue with the food analogy, here is an exerpt from a trainee journal followed by my response:

I heard some pretty good assessment types from my classmates, but in the end, each one was shot down by you and that was kind of frustrating.  I mean I understand WHY you do that and I would hate it if you didn't, but I got the feeling of "So what the hell are we supposed to use then if everything has a flaw?"  I understand the triangulation concept, but it just seems like it's so so so much work, and with all the other crap that we as teachers have to do, I don't know if there's time to do so much stuff!  What if you think of it like food?  There are SO many nutrients we’re supposed to get every day, but on the other hand we can’t consume too many calories (this was how I gained 20 pounds in my first trimester: I was determined not to have any kind of nutritional deficiency!).  On top of that there are foods you just won’t eat because they’re too pricey or you don’t like them or they’re not available…The point is to do the best you can within the limitations you have.  To continue the analogy, I think easy-to-grade exams are kinda like French fries: they’re good when you just need something fast.  Doing projects, on the other hand would be more like cooking Christmas dinner: time-consuming, impossible to do every day, but well worth the extra effort.