Sony has done a terrible job marketing PS Now. It seems like they don't even want to sell the service. for a while, it was a crappy service. They've improved the service, but haven't bothered to tell the general public. Only people who hang out in gaming forums even know what it is at this point.
I don't disagree that Sony has done a terrible job marketing PS Now. It just has bad PR. Even though the service is good, nobody knows. Not even me and I consider myself "in the know".
I do remember seeing a PlayStation Now ad on network television once and actually thinking M$ screwed up. That had what people perceive as the better service (word of mouth constantly says "the best value in gaming) but they failed to tell the public.
So, maybe they tried. They just can't overcome that initial bad press.