This is going to be a bad post because I'm not where I can look up and provide links to the supporting material, but from what I recall the cleansing of eggs also had to with different egg distribution models between the US and UK.
No, the different distribution model (refrigerated in the US, not so in the UK) is because washed eggs have to be kept cold, while unwashed eggs do not.
As far as I can tell, the only reason for the US clean-disinfect-keep cold regime is that it ensures consumers get pretty-looking poop-free eggs -- and, as a not inconsequential byproduct, don't accidentally get bird poop and its assorted nasties into their food.
