Here in Ottawa, dumping snow from your driveway into the street or the sidewalk is a bylaw offence that can get you a big, fat ticket.
Most people shovel it onto their front lawn and flower beds. The need for a place to deposit snow is one reason why even the meanest city house has a bit of land in front of it -- in fact, a metre of setback, required by the building code.

By late winter, when the city has spent its entire snow-removal budget and the snowbanks are over waist height, the task of clearing that windrow of ice lumps deposited in the mouth of the driveway by the street plow can be a real challenge; one must hoist each shovel load to the top of the snowbank -- whence it promptly rolls down into the street or the sidewalk. We're all scofflaws in March, and the bylaw enforcement officers leave you alone as long as you're at least trying to be a good citizen.

The kind of neighbourly bad-mouthing described by Penny above just tells me that these people have very little experience with large quantities of snow.