Marlowe asks, "How do you know you are going to reject them?"
"If they were any good, they wouldn't be dropped at my hotel by the writers in person. Some New York agent would have them."
"Then why take them at all?"
"Partly not to hurt feelings. Partly the thousand-to-one chance all publishers live for. But mostly you're at a cocktail party and get introduced to all sorts of people, and some of them have novels written and you are just liquored up enough to be benevolent and full of love for the human race, so you say you'd love to see the script. It is then dropped at your hotel with such sickening speed that you are forced to go through the motions of reading it."
This was back in 1953. It's an even tougher business today. But yeah this is the kind of stuff that happens with publishers. It's good advice then not to get too excited about getting a full or partial reading. The agent or editor might just be liquored up enough to think your sample pages look good.