It throws the centre of gravity out of whack, stresses the chassis, tyres, suspension and wheel alignment — so why do people choose to bump their car up onto the kerb?
The answer is to allow access for vehicles where the road is narrow.
Motorists know that larger vehicles have to be allowed access — supermarket home delivery vans, ambulances, house removal trucks, post and parcel delivery and collection vans, refuse (bin) lorries, fire engines, stretch limousines, camper vans and more besides.
On a narrow street, simply bumping up onto the kerb is enough to allow these vehicles passage without the risk of losing a costly wing mirror, having a door scratched or a wing scraped. It also allows people to open offside doors safely, and the ill effects on suspension and alignment is deemed a much lesser evil.
It is a clue that the road is poorly designed — perhaps the pavement is too wide, perhaps the road would benefit from an asymmetric arrangement, with a wide pavement on one side, and a minimum pavement on the other. Perhaps cars could be parked perpendicular to the kerb, instead of parallel to it.
Another possibility is the complete removal of pavements, perhaps with a painted line to show the pedestrian route.
What about bringing back parking in the middle of the road? Instead of concrete islands, we could have cars — that would help alleviate future parking problems and at the same time provide traffic calming.