That's a matter of definition. If a clone is created (assuming for the moment that is possible) with full memory then the clone is a person, and therefore real people.
The fact that in that book they have defined such people as 'not real people' conveniently bypasses the fact that they actually are, they're just not originals.
I find it rather ironical that you oppose an implicit philosophical position from some book by explaining another philosophical position, solely supported by another book.
That's not just supported 'by another book' but it matches what I feel about how we should treat clones. After all, if a clone is identical you'd have to come up with some pretty contorted reasoning to argue that they are 'not people'.
Also, as long as we're not able to actually do this we are bound to find our examples in fiction rather than in real life. How people think about such issues can be revealing, even if it is mostly theoretical. But you could make a case for dolphins or primates being 'people' without too much effort.
I guess you didn't read the book. It's pretty clear they are in fact not real people. For one thing they can only live a day or two before decaying. (If a clone can live longer, does that make it a person?)
For two, to the people living in that world such clones are temporary copies, and their flesh has little value - but their memories are real. In that world preventing a clone from reuploading memories back to the host is akin to murder. But killing the clone is nothing. (Is memory a person, or is flesh?)
And for three the actual clone does not consider itself a real person, clones created for menial purposes sometimes chose not to upload their boring memories back to the host, but are willing to do their menial work anyway to benefit their host. Since the clone is an extension of the host it's willing to act to benefit the host without benefit to itself, like a cell in a greater organism. Or a bee that will suicide to protect the hive. (What if the clone refuses to help the host?)
Notice how all my arguments are in the context of the book (was the reasoning in the book contorted?), not the real world. It doesn't exist in the real world and the context of how such clones are created and live matters a lot, so I won't want to argue from infinite possibilities.
And finally the entire philosophical part of the plot in the book revolves around "are clones real people", with considerably more detail and nuance than I can possibly list here, but I added a few in parenthesis near each paragraph.
That's a matter of definition. If a clone is created (assuming for the moment that is possible) with full memory then the clone is a person, and therefore real people.
The fact that in that book they have defined such people as 'not real people' conveniently bypasses the fact that they actually are, they're just not originals.
See Bladerunner.