lol, I'll go against the grain. I always washed at 60 and didn't have any problem with my nappies. If I washed at 40c though, I'd find my boys got nappy rashes and personally I didn't feel that they were clean enough as 40c isn't enough to kill bacteria in poo filled nappies.
i used to religiously wash it all at 60 to kill bugs. but then i had to put my logical hat on. we have bacteria on our hands from all sorts of things including sorting the dirty nappies. we trust that our soap will kill the bugs, we (well most of us) don't wash our hands at 60 in order to achieve this. the washing powder is just a soap formulated into grains instead of a bar/liquid. so i have to trust that it will deal with the bugs.
so now i always wash at 40 unless dd's having a particularly bad day with really icky poos, which she seems to have quite often lately.
I get what you are saying, but I don't think a pile of smeared poo, on cloth, is quite the same as wiping with a wipe and then washing skin. Quite different 'materials' being washed. For me it was more about the nappy rashes, I'd rather wash at 60c and not have the rashes, than wash at 40c and have my child in discomfort