Blame the appliance manufacturers
Most dishwashers sold were merely a gimmick. IMO pre-rinsing comes from normal healthy able minded people using GE, D&M, Westinghouse, Durawash, any machine that lacked an actual fine filter. Followed by poor spray patterns, short prewahses, too short main washes, excessive pump water carry over, and inadequate or no water heating in the main wash. 90% of all DWs installed in homes merely fountain-ed unfiltered water, and still those that didn't had other performance marring flaws.
I come to this conclusion from my own mother whom I convinced to start using the GE DW in our new place. At the time I knew nothing about appliances and we were all happy we'd never have to wash another utensil. We were wrong. We loaded everything as is but after a few loads with particles on everything, even trying various DW detergents like Cascade, she started prewashing everything spotless. Called maintenance and then a repair tech who both said nothing was wrong with the machine and that it was essentially normal to pre-rinse dishes beforehand. The next load she told me "DWs are a gimmick" with the rest of the rest of us disappointed saying we had a feeling it was to good to be true.
Thinking about it the whole experience makes me very angry. A simple pull out fine filter in the sump would have solved the problem, but for some reason manufacturers thought it better to take large food particulates and redistribute them as thousands of smaller ones.
Despite having a Whirlpool built Maytag, my mother still pre-washes everything. I keep having to remind her but she says she doesn't want to chance it. I now understand the saying "you never get a second chance at making a first impression"
Truth is unless a DWs can't take scraped dishes that haven't seen a single drop of water post meal with several days of dried on food into spotless residue free, particle free surfaces then its a gimmick.
Outside of the WP Power Clean Filter Module, WP Point Voyagers, most Maytag JetCleans, some back filter orbital GEs and some modern machines the rest are simply expensive decoys.
If you want energy efficiency laws to work, don't regulate how much water or electricity an appliances uses but rather its performance. Performance dictates energy use. Not the other way around.