We have nothing to blame for this but our willingness as consumers to continue to buy from companies that do this. It just rewards them to continue the trend.
Part of the process is slipping incrementally worse stuff past consumers. ATMs were an improvement, they did things 24 hours a day. Ditching the tellers after everyone used ATMs is shoddy. Offering scanners for 10 or fewer items is an improvement. Scanning every damn cart because there's only 1 checker makes the whole thing worse.