I'm an Indian and a hindu. I've been to that temple. It's really sad to think that there would thousands of people around that temple who would go hungry as we speak and this temple has wealth that will pretty much stay locked up for the rest of humanity. It'll never get invested. No next google would come from thiruvanandapuram because of this. People would go on their lives living in terrible houses, driving terrible vehicles on atrocious roads. And Hindu fanatics would organize protests at the first mention of using this for any practical purpose.
Considering local government corruption, I'd actually be happy if it wasn't used for 'practical' purposes if the government gets to control all this wealth.
I doubt it is the lack of money which is the primary cause of the state of our society. No amount of money can bring out a society from the corruption & mismanagement. By all means, let us use part of the treasure for public good (I say part since I assume the historical/antique value for majority of it). But unless we manage to fix our system, we will be back to broken roads and shabby houses very soon.
It's about feeding a man vs. teaching him to find his food. All the collected wealth will vanish if we use it to feed people. People/Communities/Governments have to learn to build wealth and not live off it. Some part of this can go into making the land a better place but I think the most important use of it is to make the people proud and want to live better and build more wealth (hence standard of living). A large part of this treasure should be proudly displayed in a fantastic Museum.