@Kika2901 - it is about everyone being considerate and sensible. I walk slowly, and I do my best not to get in people's way - I try to be aware of my surroundings, and if there are people in a hurry, I will let them past if I can, or I will walk closer to the wall, so they can get past.
A toddler can't have that awareness of their surroundings, so their parent should be aware for them. If there is a big crowd of people champing at the bit behind you whilst your toddler dawdles all over a narrow pathway, you need to have that bit of awareness, and maybe either move to one side, or take your child by the hand and get them to speed up a bit.
Parents need to have a bit of common sense about where they can let their child range freely, and where they can't - if you are in a busy environment, with lots of people rushing round, this is not a good place for a child to toddler around - it is dangerous for them and risks annoying other people. Likewise a coffee shop or restaurant with people carrying hot food and drinks around.
People do lead very busy, hurried, stressed lives - is it fair to make their lives that bit harder by letting a toddler find their feet and dawdle round somewhere busy, when they could do this better and much more safely somewhere else?
There needs to be give and take from both sides, but I don't think it is unreasonable to expect toddlers to be kept reasonably close to their parent and not under busy people's feet in busy places.