Goodness sake Michael, now you're doing a Roz by going OTT on Brian's comments of which he's perfectly entitled to as much as the liberal brigade on here who on the whole have put their points across sensibly.
Not all of us think every parent is ignorant when it comes to transporting kids, we even have one member who has demonstrated common sense when it comes to using his buggy, however look at the buggies practically, the larger modern buggies are not designed to go through the front door and the narrow passageway to the wheelchair area, which does cause problems especially at peak times.
It's a hard rule to enforce as no government wants to be seen to putting rules against parents of young children who have a hard task in itself before even getting out of the house.
Incidentally I would apologise to Roz on one point, there is a shared allocated area for buggies and wheelchairs....on the Northern Line!