Thank you for contacting us. When it comes to buttons, each platform has its own default styling (background, borders, font-weight, and size. etc.) The styling provided by the Kendo UI Mobile skins does not try to override these, as some people my prefer it this way. If this is an issue in your project, than you should avoid using buttons and resort to A elements instead.
Join us on our journey to create the world's most complete HTML 5 UI Framework - download Kendo UI