Yes, one has to consider, that until rather recently, the largest front loaders held about 5kg to 6kg. Only with the advent of front loading washers being pushed onto Amercian consumers, have such units grown to handle what most Amercian housewives call an "average" wash load.
By and large American housewives have treated laundry the way their mothers, grandmothers and such did; a time consuming chore, done once a week (if then) and best gotten over with quickly. If you had told Mrs.Average Amercian housewive back in say the 1050's or 1960's she had to make due with a small capacity front loader, that took ages to complete cycles, you'd have women up in arms from coast to coast. With a husband, several children, plus herself making up laundry for wash day, that simply is too much washing for one day.
Consider also that all the above washing back in those days for the most part had to be ironed. So doing laundry every day, as many European housewives did, would also mean ironing several times a week, something many women didn't enjoy once a week.
Even when one allows for various configurations of agitators and "features" which for the most part pretty much did nothing, but distinguish one brand of washing machine from another, top loading washers are easier to produce and have less problems than front loaders. Top loaders do not require door seals/boots, nor do they require complex suspension systems. What you've go is not far from the first top loaders by Maytag and such, a tub that holds water, with a center post mounted agitator. Once electrical motors came along powerful enough for spin cycles, which made wringers obsolete, there was no looking back.
L.