whirlygig,
I definitely agree! And the trouble is, not a lot of ATCOs realise that. They see us hovering and it looks easy, so they don't realise that it's taking all our hands and feet, a lot of concentration, and that at the same time we're possibly coping with a crosswind (LOTS of foot work needed for hovering in a Xwind, for those who don't know), trying to work out where to go in an unfamiliar place, and making sure we don't blow over any light PFA-type aircraft or hit anything with this long tail which we can't actually see.
They direct you on some complicated rotary-only route into the airfield, and then give you taxi instructions as you're approaching and coming to a hover. That's OK...but they expect an answer too!!!! NOW, not when you've actually come to a hover and feel more under control!!!!! At least with a f/w aircraft they don't give you taxi instructions till you've landed the thing.
OK, so I'm exaggerating just a little bit as usual to make my point.
But whirlygig has a good point, which is true more generally. When the workload is high, talking is just one more thing. And for low-ish hours pilots, f/w or rotary, the workload is often high. And to try to talk on the radio under those circumstances may be just one thing too much. And if you don't do it well, and feel an idiot, or the controller gets annoyed, it becomes harder the next time...and so on........