Is that really an argument? Struts uses JSP and
Servlets and those aren't integrated in the same forum...
There will always be areas where there is a possibility of confusion as to where a question is best placed but that should be no reason to not divide the forums into managable chunks.
If Struts indeed covers the majority of questions in the forum to the point where other topics are lost in the noise it is probably time to give it a forum of its own.
Seeing the amount of Struts questions moved from the JSP forum to the web frameworks forum that might well be the case.