I'm a firm believer that a truly "great" book will be fairly spoiler-proof (and I'm not very "spoiler" sensitive to begin with). But having said all that; the "study" seems pretty silly to me. It's about a preference. Many readers simply
prefer to enter a relationship with a new book as spoiler-free as possible. So they do; and they like it that way; and their wishes should be honored (within reason) by others who love reading.
It has nothing to do with what
is (or what might be
better). It's about what a reader
wants. It hurts no one for a reader to deceive themselves a bit about the "real" effect spoilers might actually have on them.
Is the purpose of the study some sort of weird attempt to justify being an a-hole and blurting out what some consider spoilers willy-nilly?