Yeah it's a strong signal, but I think it's not as rare as people make it out to be. It's common enough that it finds use, but the indicator itself is more reliable if it's in the direction of the long-term trend. ie. positive divergence at the bottom of a short-term pullback in a longer term uptrend.
Take it as it is.
Of course, there has also been negative divergence in the indices.. so.