YES, we've all seen team mechanics pressure washing bikes with ZERO ***** given about bearing and such.
Here's the thing, though, first off, those bikes get rebuilt and re-greased fairly often, so it's not a huge deal to be a little reckless. Plus, it's not like they keep bikes for very long anyways, so longevity isn't much of a concern.
Another thing to consider is the rider of bikes we are watching being sprayed down like they're on fire. These are usually support riders, and team mechanics don't care as much about their bikes. You can bet that Chris Froome's bike doesn't get that sort of treatment.