Woah, Woah .. It was never Periyar vs Tamil Nadu. It has always been Pariyar's Tamil Nadu. Keep that in Mind. If you are not from Tamil N adu I'll think of you as ignorant. But if you are, then I'd like to think of you as stupid.
As it was said in this interview, you only want to retain this stupid opinion about periyar. It is totally upto you though. This is what I would like to think as achievements by periyar.
1. Starting a movement for Social Justice 2. He fought against untouchablitiy 3. Started or Inspired Anti-Hindi Movement 4. A lot more that I don't know of..
Now lets see why the first three points make sense as of today
We have a more socailly equal society in Tamil nadu than elsewhere in the country. Look at all other states and compare the participation of people (people from all castes) from all castes in Schools, Colleges, Government Jobs, All professions, Politics, etc. You could see that it is very widely distributed. Of course it is not perfect, but it is the best in INDIA.
2. His contribution is more than Gandhi's in untouchability. Gandhi could not help those people enter temples. He Did. He is one of the first to support inter caste marriages and was vehemently against superstition. Of course many brahmimns made a living out of other people's superstition was not periyar's fault.
3. Without him Tamil as a language would not be what it is. When I look at Maharashtra, Gujarat, Karnataka, etc. I pity marathi, gujarathi and Kannada. More people want to speak hindi and english than their own mother tongues. Learning other languages is welcome but not at the cost of mother tongue. You should always know who you are.
So yeah, PERIYAR is a Great Hero in Tamil Nadu. And if Hero Worship took us this far, then it is not wrong to continue it. Just look at any other state in India where there is no Hero worship and compare that to Tamil Nadu and you could see that Tamil Nadu is lot better.