Crying is a necessary evil, whether you are grieving or not.
There are plenty of reasons why I don't like it- I'm not a pretty crier, my eyes inevitably end up looking like little brown M&M's when I'm finished, I usually end up exhausted or with a headache (if not both), and it makes my mascara run.
That said, I've learned over the past year that it is so much better to cry than not. It really does release something inside that needs to get out. Each tear I've shed has been with a purpose. The times I've tried to hold back lead to a huge cry fest somewhere in the near future, but the times I give in I find myself strangely peaceful afterwards.
In high school, my friends and I used to call a crying session a "mental breakdown"...but honestly I think releasing tears builds you up more than it breaks you down. Crying is just another step helping you to look life in the (albeit puffy) eye.