I just did a quick test to see how much trouble it would be to get tix to, say, King Kong... saw the list of dates as soon as I clicked on the show link, and when I picked one I was prompted to complete my purchase.
Is the problem perhaps simply trying to snag harder tickets? I imagine tix that show up for Ferryman will be snapped up more or less immediately, and that those results are likely to be more hit or miss. Perhaps they just need to tweak the code so that those shows disappear from the listings more quickly after all tickets are purchased. I'm not prepared to ditch my membership over it, though.