You are right that diesel is usually popular in those countries where diesel fuel price is much lower than petrol...otherwise petrol is preferred worldwide if fuel price is similar.
In the past there used to be a reliability aspect when during the era of carburators, ignition coils and distributors petrol cars would often give trouble especially during rain or on long routes due to this problem or that...but after EFi and electronic ignition, petrol has become damn reliable.
During old days, diesel engines would not suddenly seize because they did not use distributors, spark plugs, ignition coil etc..so they were more dependable, however they had other problems which were common with petrol as well such as overheating, needing overhaul etc.....but in general more dependable than petrol.
In todays era, situation is opposite, as poor quality diesel can suddenly seize modern diesel cars....not so for petrol
