I have to agree with those who have said that the issue is not so much the 'sexualisation' of children. I think it's more that there is a commercialisation of childhood which is where the pink alternatives come in.
I also think the problem is that the line between adult and child is becoming blurred as more people have an extended freedom in their 20s. So, for example, Little Miss Naughty knickers start to break down the divide between adult and child. Equally, children have more choice now because they have been made consumers and the parents' role is not so obvious.
I was thinking about high heeled shoes the other day. MIL wanted to get DD (almost 3) some high heeled dressing up shoes but I refused. However, I let her go round in my shoes? I think the difference is her role as a consumer. In my shoes she is parodying an adult, in shoes which are designed for her, are the right size etc. she becomes a consumer.
My thoughts on this are quite confused so I hope it makes sense!