If TopLevelItemDescriptor.newInstance throws a RuntimeException, why are we...

If TopLevelItemDescriptor.newInstance throws a RuntimeException, why are we wrapping it in an IllegalArgumentException?
Let it throw something like Failure and control the rendering.

core/src/main/java/hudson/model/ItemGroupMixIn.java

@@ -258,12 +258,7 @@ public abstract class ItemGroupMixIn {
         if(parent.getItem(name)!=null)
             throw new IllegalArgumentException("Project of the name "+name+" already exists");
 
-        TopLevelItem item;
-        try {
-            item = type.newInstance(parent,name);
-        } catch (Exception e) {
-            throw new IllegalArgumentException(e);
-        }
+        TopLevelItem item = type.newInstance(parent, name);
         try {
             callOnCreatedFromScratch(item);
         } catch (AbstractMethodError e) {