Maybe, but I wonder if that is true at night with the lights off. When I read in bed at night, I much prefer light on dark text. Combined with Android's night mode to tint things red, it is fantastic.
In fact, I wish the Kindle Paperwhite would come out with an inverted mode already (although I think I read there were some challenges with doing so). It can be fairly straining on my eyes to have the sidelit screen bright enough to be legible while being as dim as possible to make reading with the lights off comfortable.
Majority of reading is done in a brighter setting so many factors contribute to using dark text in white background. In the case of reading in the dark or low light settings, using a Kindle Paperwhite gets complicated since you want to make the background darker while still maintaining sufficient contrast to read the text which is always in a dark font color.
In the UX StackExchange post, it's stated that astigmatism is also a contributing factor to favor dark text on white background. I do believe that these night time settings should be toggled automatically for white text with dark background as well as accounting for blue wavelength reduction for screens with full colors.
I would like operating systems, browsers and websites to globally support a "night mode" where a dark background is used. Especially with the proliferation of mobile devices, people increasingly use technology in low-light environments. As it stands today, I have to add external stylesheets to websites to get this effect, and if I want to toggle them, I have to toggle each one manually. It's similar, but worse for Android apps because the app itself has to support themes.
I find having a significant portion of the screen white when my eyes are relatively dark-adapted uncomfortable, even when the brightness is set fairly low. I find a dark background with light text very preferable under those conditions. I do not care if there is research suggesting I should not have this preference.
From talking to others in person and online, I get the impression that my preference is very common. Android was supposed to get something resembling this, but the feature has been dropped or delayed.
In fact, I wish the Kindle Paperwhite would come out with an inverted mode already (although I think I read there were some challenges with doing so). It can be fairly straining on my eyes to have the sidelit screen bright enough to be legible while being as dim as possible to make reading with the lights off comfortable.