Ah, thanks Wow. I did think that pulling it on the basis of four posters on Mumsnet on a Sunday night was a bit extreme - as was monitoring MN Property thread in the first place! But yes, a MSE thread would have generated an unexpectedly high hit rate... At least they responded, give them credit for that. And EAs can only go with what the vendor wants.
The photographer who came to do our pics said that he often has to move mouldy dishes out of kitchen sinks, pick up clothes etc, but he needs to check with the vendor first. If he phones and the vendor says 'don't touch a bloody thing, people are buying my house not my stuff anyway', there's not much he or the EA can do. Our EA popped in as the photographer was nearly done, and they had a conversation about another house which was too filthy to take photos. Apparently it was the second time the photographer had been sent. The EA then decided to drop the house from his books because it would damage the EA's reputation, but he's lucky, this is London and there are plenty of better-presented properties.
I imagine that a small independent EA in a less densely-populated area might want any and every chance of commission - you've got to feel sorry for some poor sod trying to sell a place in a state like that. And can you imagine actually doing viewings? The EA should offer to get the place cleared up, belongings boxed and sent to owners/family or disposed of as directed and a professional clean - but up the commission to compensate or add an admin fee to the costs.