The tradition in most homes is to use the kitchen not only for cooking but also for socializing and having meals at a dining table set in the kitchen. Also, mornings are a hurried time, when people are keen on getting out of the house to their various activities on time.
There is no time to sit at the table for breakfast and the counters are used as breakfast bars. The height of standard chairs make them too short for the counter thus kitchen barstools are pulled up at the counter.