No, not robots. Humans who had their Personas artificially awakened. They wanted to investigate Tartarus and the Dark Hour but didn't want to wait for natural Persona users to randomly show up, so they rounded up a bunch of street kids and forced their Personas out.

There were three survivors. And even they had drastically reduced life expectancies because the regular treatments they needed to keep their Personas from turning on them and killing them - or worse - were also lethal.