Well, that assumes that this is the only individual in India that could be interested in the market segment. There are plenty of people in India for whom USD $500K is not a lot of money, particularly if a solid case can be made for the investment.
He could have invested four years trying to raise money to buy a number of industrial grade machines rather than doing what he did.
Here's another interesting data point. According to this site (http://www.euronuclear.org/info/encyclopedia/n/nuclear-power...) the average nuclear power plant in India produces 200MW of power. Deploying enough machines to provide napkins to the TAM would consume around 6% of the power output of a single nuclear power plant. An operation based around industrial machines would require about 4%. It's interesting when you can measure things in terms of the percentage utilization of a nuclear power plant.
I looked through the various responses to my post. Lots of good points. Of course, the infrastructure in India is something I cannot have a good grasp of from my vantage point in suburban Los Angeles. When faced with something like this I always fall back to one of my favorite Mark Twain sayings: "A man holding a cat by the tail learns something he can learn in no other way". This inventor held that cat by the tail. Hard to judge from the outside. I'll have to leave it at that.