I haven't even looked at the book, but I'd tell him to look for a new publisher. Any publisher who will publish a book based on likes from Facebook isn't interested in publishing quality works. I read a lot. 2 or 3 large novels a month and most are on my Kindle. Amazon has made it very easy for individuals to self publish the works. The problem is, most people don't ever look for criticism of their books. Their family and friends read it and then blast away with 5 star ratings. You can go to many highly rated self published books and check the other ratings of the 5 star reviewers only to find that most have only ever reviewed one book. That is with very few exceptions, I will only read books from major publishing houses.
IMHO. If it is decent effort, they should shop it around to multiple publishers. Based on rejections, which will always happen (I have several), they should be able to glean some feedback to determine why it was rejected.