Right, right.. ok well like I said before, Chakra originally stemmed from the juubi. So it's only trying to get it all back, just like it says in the manga. The princess stole the juubi's fruit, it got mad at her for stealing its chakra and only wants to get it back...
Also, the sage sealed him in a moon-sized chibaku tensei, and the juubi remained there dormant for over 1000 years or who really knows when. So now that he's around taking chakra, it sees it as the people who have learned to use his chakra thanks to the sage teaching them... This is only my opinion on it, though it's not to be taken as fact, the juubi probably thinks it's still the era of the sage.. it didn't live through the generations to see madara and hashirama grow up, it didn't see shinobi villages... what it knows since being sealed is man possessing its chakra and its trying to get it back.