We have been in Unawatuna for a few days now and I must say I've been quite sad to see how some tourists behave towards the locals. I've travelled a fair bit and have found Sri Lankans to be some of the nicest people around.
I know it can get a bit annoying when you're asked for the 80th time if you want a tuk tuk or a trinket on the beach but it doesn't take much to show some compassion, these are people, the same as you or I and they want the same as we do, to be happy, safe and have food for their families. Think how hard it is for that old guy pacing the beach all day in the heat trying to sell a coconut or 2.... not an easy life. I just think it takes nothing to be polite and smile and say no thank you. And actually, the nicer you are,the more you get to know people and really experience the place.
I'm sure most people are nice but I've really seen some very very rude people here shooing people away, ignoring them and shouting.not good :(