It is lame because a company like Google should be able to provide a Linux version of its perfectly serviceable photo organization and basic editing app. I know they don't have to do what I want them to do, but "pfft...", y'know?
Support for all three platforms is a requirement for me (and most other developers I know) these days, it's one of the reasons why I haven't bought various standard tools including Photoshop... yet use Filezilla, Gimp, Sublime Text 2, Firefox, Thunderbird, Open Office, Clementine, etc.