The JVM took too long to achieve that ideal in a way that actually worked for end-user applications. Early java-based client applications had a horrible user experience. Version conflicts were very annoying, especially on windows where you didn't have a command-line culture comfortable with simply switching between versions by modifying PATH and JAVA_HOME. And even when you didn't have version conflicts, Java applications had slow, idiosyncratic GUIs that often did not support basic and common features like ability to copy/paste or switch to arrow-key navigation through menus.

And on top of all that, it would still be more memory intensive than an equivalent native win32 application. Developers usually only shipped java-based UIs to Enterprise Software users who had no choice but to use what their bosses told them to use.