I actually block WIPs all the time. This has become easier since I bought some very long cables for my laminated wood interchangeables; I can just replace the needle tips with the plastic endcaps, and the cables function as flexible blocking wires. (Compared to knitting, blocking crochet in progress is so easy it feels like cheating: just replace the hook with a plastic coilless pin-style marker.)
Here are a few of the reasons I'm frequently pinning something out just before bed:
And sometimes, I have more than one project going at a time. (I know, you're shocked!) Usually one of them is The Thing I Am Currently in Love With, and another is The Thing I Need to Get Done. Sometimes the only way I can force myself to stop working on the first is by blocking it in the morning. That way, I only have to be virtuous for the thirty seconds it takes to shove the object of enchantment into the sink; then for the rest of the day, I'll have to work on the object of drudgery until my beloved dries.
(Or, uh, cast on something else entirely...)