> OTOH, the robots will ignore your complaints and never try to be friendly for a higher tip ...
No worries, my credit card company listens to complaints. And you know, those are the best kind of complaints, because they get your money back.
In the end, robots will be extremely friendly ... because they have no sense of "fairness" or self-interest ... only a programmed instruction to make the customer happy or if things really get out of hand, to call the cops.
