Bro, I agree to the fact that tuning is not necessary so much as to have your bike tuned regularly. My CD 100 has completed more than 14,000 km but I have only had it tuned three or four times. To me, tuning is just a wastage of petrol. Just keep changing oil regularly and have the air filter cleaned at regular intervals. Get the clutch, accelerator, and brake wires lubricated when you feel even a slight hint of friction in them. That's it!
If you still feel like tuning the bike, don't do it much often. You can do it after a few thousand kilo-meters.