That was always my thinking Minipops although I'm sure it's something to do with the milk and bacteria. Don't know how many times dd has burped over a toy or something and later it's in the mouth. I'm always fastidious when washing bottles and they get a good rinse with hot water after (hence the old woman chapped hands) so can't see me hoking the steriliser out of the outside bin. Ds was prem and he was grand with just washed bottles after the 6 months, although if it was a year then I would have done it until then. Never had an upset tummy. Funny how things change and now I feel a bit like a bad mum for not following recent guidelines.
I got told 6 months by an NCT instructor, who shrugged and said that by the time they are licking the cat, who's going to worry about a bottle or two?... I thought it was a pretty good point! We still sterilise and will to a year actual, but no later - I'm not carting the damn steriliser to NZ with us!!