It's apparent that execution left many things unconsidered. Having a high-denomination bill (Rs. 2000), which is practically useless for most purchases, and insufficient quantity of the low-denomination bills (Rs 100), is as bad as it gets; the transition is going to fairly painful for the whole population.

That being said, I would avoid lamenting the troubles of middle-class and poor when the rich are going to be unscathed. It's true that some leaks would impossible to plug, and people would find clever ways to get some of their money through, a great deal of ill-gotten riches is going to affected by this. It'd be almost impossible to launder monstrous amount of cash that sits inside coffers of those who invariably assumed that they were immune; the mandated limits simply make it impractical.

When you're buying a house in India, there is no way you can go about it in honest means. The seller would usually ask half the amount being handed in cash to avoid taxes. Almost everywhere, a large slew of businesses always avoid paying any kind of tax. The pattern is so ingrained that it's almost become a habit. And this is only tip of the iceberg — political donations, bribes, illegal trades, hawala all stem from the same thing.

Maybe I am speaking from an ivory tower, but if this instills a good habit in minds of people — of being part of a transparent economy — probably the benefits would far outweigh the cons.