To counter this prejudice self-publishing authors should make their books as good as books produced by the professional editors, typesetters and designers employed by the major "traditional" publishers.
Sadly, sometimes the work of the pros should not be emulated.
Car Guys vs. Bean Counters was published by Portfolio, an “imprint” of Random Penguin. That's the informal name for the merged Random House and Penguin Book Group. Penguin (even without Random) is one of the largest book publishers in the world and started in 1935.
A publisher with vast size and long experience should know what it’s doing, but it doesn’t always do the right thing.
A few years ago, Penguin's Riverside imprint published a phony autobiography, Love and Consequences. Before the hoax was revealed and the book was recalled, it received an excellent review in The New York Times.
Bob Lutz’s “Car Guys” book exhibits a much smaller sin -- a silly typesetting error which should have been noticed by one of Penguin’s experts before printing. It’s mostly a good book, otherwise.
In this case, "professional quality" is not good enough. Amateurs should do better.