Let me just start by saying I intend to do BLW and therefore am not worried when my baby starts eating solids, knowing that he will when he is ready. But I was discussing this with a few of my NCT friends the other day and they all seemed to have this very strong idea that you shouldn't leave a baby past 6 months without introducing some sort of solid food, and they were confused as to the advice - you mustn't wean before 6 months, or after 6 months - leaving you one day to wean the baby!! I'm sure this can't be right but I found myself unable to explain since I'd never heard the "don't leave it any later" argument before and have no idea where it comes from.
Also a couple of them had been to a weaning talk (I think) where the HV had mentioned this no later than 6 months rule, but that they needed to start on purees first, so using logic they had interpreted that it was better to start weaning as early as possible to ensure a smooth transition from just milk to purees, to lumpy foods, and finally to finger foods.