OP YABmassivelyU.
You can not block an exit on a train, no matter what your excuse. If the exits were full, you were presumably asking people to walk down the carriage and fight their way through another crowd of people at the other doors, meaning they could very well have missed their stop.
I commuted into central London every day for almost 9 months, with my baby (she was in my staff nursery). We did it with slings and/or the buggy, I've found commuters, much like people in general, to sometimes be helpful and sometimes be rude. But when you are planning to get on public transport at peak times then you need to do as much as humanly possible to minimise the disruption you cause; not least to help yourself!
So if I had the buggy with me (which collapsed into two parts), I would make sure I either got on the train in the wheelchair/bike/buggy storage area so I could park up, or I would choose to get the bus which had a designated buggy space, or if neither of those were possible I would arrive in good time for the train, put DD in a ring sling with my stuff in a rucksack, collapse the buggy (it was two parts so a pita but it was possible) and get on that way. Invariably when watching me collapse a buggy and carry the parts with a baby in a sling, someone would help me.
And if the train was utterly heaving and I had the buggy with me then I just wouldn't get on, same as I wouldn't attempt to get on a crushed train with a tonne of luggage or a bike. I would wait for the next one.
I wouldn't risk my baby in the crush and I wouldn't want to inconvenience anyone else further.
Travelling with small kids and luggage etc can be tough, that's why you need to plan ahead, do as much as you can to minimise inconvenience to yourself and other passengers.
Acting like you did is not going to win you any help.