Publicly, "Why We Sleep" is viewed as a motivating 2017 international bestseller—hitting #1 on the Sunday Times and #8 on the New York Times lists—that popularized sleep science and prompted many to improve habits, thanks to mainstream praise for Walker's accessible explanations. However, academics largely dismiss it as alarmist and riddled with errors, a consensus solidified by Alexey Guzey's November 2019 essay and subsequent discussions despite Walker's blog responses.