Something that shouldn't be overlooked
Most, but not all, top loaders have water level adjustment. On many older models it was infinite; the Whirlpool I use has 5 levels. I can wait 3 weeks to do my underwear, and have a full tub, but I choose not to have that much dirty laundry sitting around. It might be slightly more wasteful of water, but there's no water shortage here. I do know people who wait until they have no clean clothes and then stuff in as big a load as they can.
It may be that people on this site tend not to want piles of smelly clothes and thus do smaller than average loads, but we have more single people than normal, too, and I'm sure families tend to wash fuller loads.
I don't know if that helps answer the original question or not.
Most, but not all, top loaders have water level adjustment. On many older models it was infinite; the Whirlpool I use has 5 levels. I can wait 3 weeks to do my underwear, and have a full tub, but I choose not to have that much dirty laundry sitting around. It might be slightly more wasteful of water, but there's no water shortage here. I do know people who wait until they have no clean clothes and then stuff in as big a load as they can.
It may be that people on this site tend not to want piles of smelly clothes and thus do smaller than average loads, but we have more single people than normal, too, and I'm sure families tend to wash fuller loads.
I don't know if that helps answer the original question or not.