In the US 1 hour cycles skimp on heat and doing so give terrible results. Clean dishes and fresh interiors come from 4 hour cycles. However even the 4 hour cycles can not handle the amount of soil that a Whirlpool Power Clean Filter Module could, forcing some level of pre-rinsing.
People thought they would be happier with a quieter dishwasher at the expense of taking longer and as it turns out people would rather put up with 45 minutes of noise than design their day around a 4 hour cycle.
Some people want to put the dishes away after lunch or dinner, others want to load up their dirty pan after being outside and have it ready in an hour for the next meal. Some people actually find it more convenient to run smaller loads with a full standard tub than wait for their tall tub to fill up with everything in the kitchen including utensils and bowls which they might need more than once in a full wash period.
I myself much to frequently run partial loads because when ever a meal fills my tall tub full half the dirty dishes and bowls end up being left on the counter because there is no room for them inside the machine. I rarely had this problem with my standard tub. 3 meals were just enough to fill the machine 1/3 full each time. So at the end of dinner typically everything fit inside, cycle ran, and it was ready in 1 hour.
