Wondering why there's no Kindle for Web

It seems really logical that Amazon would add a Kindle book viewer to their web site. Then, it wouldn't matter what operating system I'm running. Currently, Linux users are left out in the cold. Aside from that, I think many users might prefer to just user their browser rather than download a client.
I don't currently have a Kindle, but I do have Kindle on my Android phone and the PC client.