Unless you play older worlds than this you won't understand. At this moment in time, nobling any barb lower than 6K points is seemed as noobish but when this world progresses to something like w17 (using it as my example because I play there), some players are ORDERED to take the barbs, this is because eventually tribes push for 100% K dominance, and by this I mean, getting rid of the barbs too so that no-one else can noble into our K's.
We control something like 99.5% of 4K's in my w17 tribe and there are hardly any barbarian villages going except for those that crop up when players delete.
We have to face the facts that eventually this world will become full of barb munchers to protect K's. It is vital, there is no point in taking out all opposition in your K if there are plenty of barbs for people to move too.
PRIME and KILTOM are currently doing it in this war. PRIME took barbarians in KONG territory and stacked them and grew from there. This will eventually bring tribes down as your clusters get bigger an bigger in your oppositions territory.
In w17 I planned a 75 barbarian village OP. You might think an OP on barbs? WTF! By OP I meant we all had to land within 12hours of each other with 10 villages of D landing at each village within 3hours of the village being taken. We then gained huge territory in our opponents territory and we are pushing them back hard from there, we have 75 villages with 750 D's worth stacked in them, atleast and we keep pushing them.
It will eventually come to this world, no matter how frowned upon it is.