WSDL/SOAP are not REST
Well if you define REST as "Web Apps developed with RoR" then I guess you're right, Rails is definiteley the pioneer of Rails development.
You've yet to refute that argument
There was (at least) Tomcat deployed and quite popular, and yep, everything moved through REST interfaces. Even with that one and the huge success it had in the enterprise world, I wouldn't dare to say that the success of REST relies on Tomcat anyway.
REST hit it big with the www, www is REST's killer app. Those things are quite literally the first ones you should know when you start developing for the web.