Because the Android default browser had no SVG support until version 2.3, allegedly to save 1MB of space. These older versions will remain in widespread use for

Because the Android default browser had no SVG support until version 2.3, allegedly to save 1MB of space. These older versions will remain in widespread use for a while yet (slower upgrade rate than iOS) and Raphael doesn't fill the gap, unfortunately. Opera Mobile and Mobile Firefox do support SVG, even on old Android, by the way. (Disclaimer: I work for Opera.)