Why natural languages have grammars

This occurred to me after reading several NetKernel forum entries crying out for help with NK's "declarative syntax". I think there are some great ideas in NetKernel but the idea of burying your programming language within XML is not one of them.

<sentence>
 <np>
   <verb type="gerund" subject="true">Programming</verb>
   <pp>
     <preposition>in</preposition>
     <noun type="proper" acronym="true">XML</noun>
   </pp>
 </np>
 <vp>
   <verb tense="present">is</verb>
 </vp>
 <np>
   <determiner singular="true" indefinite="true">a</determiner>
   <noun>pain</noun>
   <pp>
     <preposition>in</preposition>
     <determiner definite="true">the</determiner>
     <noun>ass</noun>
   </pp>
 </np>
</sentence>