If it were January and you were on the Norseman East Hyden Road in the days when you would have been on horse back, for then it was but a track in the bush, this rock would indeed have been a disappointment, you might have been left in the lurch, without water.
Back in the day when Charles Hunt explored the W.A. interior (1864 onwards) for the crown and built wells and damns, Hunt was schooled by his indigenous guides to look to the granite rocks as places of water. Granite is a natural pump and if water is under or near the rock it will be drawn to the surface, or close enough to dig for. Granite is also a water collection point, rain runs off the rock and gathers around the edge in pools or in gamma holes. Merredin and Berimbooding rocks are prime examples of good water supply, and additionally have granite roads or channels built around them to guide the water to a central point, as seen the bottom left of the photo below:
But Disappointment rock seems to have no gamma holes and the winter creek was not substantial, and in spite of the fact that it was raining heavily when we passed through. In fact there was more water on the road than in the creek. So disappointment it was in terms of water supply. And in days of yore you’d definitely be left in the lurch if you’d foolishly hoped that this granite rock would help you. Between a rock and a dry place.
Appart from that it did have nice views of the surrounding woodlands.