I think a better way to phrase it would be "Kindles are clearly a superior device for reading [novels and similar material] than iPads."
An iPad obviously is better for things like glossy magazines, graphic heavy books/PDFs, etc. However as a replacement to my "books" then the Kindle wins over the iPad.
Also the Kindle Paperwhite (and Kobo Glo, etc) are pretty great for low light reading. I agree the old lights were a bit annoying although the Amazon leather lighted case has always been pretty decent to be fair.