"my and my childrens right to travel"
"those passengers preventing my children from getting on the bus"
If that's YOUR attitude Roz I'm really not surprised at the reaction you get from some people. Let's remember those people already on the bus have paid their fares and have just as much right to travel as you and your children do, and their reason for being on the bus is probably just as important to them as is yours.
Its a good job you are obviously not old enough to have been a bus user in the days of the Routemaster. There wasn't room for any sort of pushchair/buggy on those and if you didn't have something small enough to fold and put under the stairs - with the conductors permission - you didn't use the bus, you walked.