Well my dear, that’s a completely new set of questions. Earlier you asked how and I think that has been clearly answered.
And if it wasn’t a military objective it should have been declared as one, instead of the Al Jazeera broadcasting studio or the Palestine hotel perhaps.
Instead of asking “why” I think “why not” would actually be more accurate: It would not have taken much resources - and I don’t think you need special forces for that - to protect it and there have been reports that US soldiers, present at certain sites, have turned a blind eye to looters or even encouraged them. While I personally couldn’t care less of people steal some chairs and tables the art stuff is certainly a totally different thing and a great loss. You can argue about how much art the US has, I don’t see how that justifies to ignore the heritage in Iraq!?
Other more “important” sites were secured and IMHO soldiers haven’t been attacked there in the manner you and Okami argue, i.e. it’s too dangerous and thus not worth it. Instead of rockets the organized ones had the keys.
Lame excuse IMHO and yet proof again that the US only cares for their own interests (i.e. those who directly profit them).
Just to make this clear: nobody said you should have protected the museum instead of other places (incl. “your” oil ministery) but I believe the museum deserved to be protected, too.