The problem with reducing pricing in general, any product or service, doesn't matter which, is that the lower you reduce a price and the more often companies do it, the perceived value of that item drops and won't recover for years. (it can take up to seven years for prices to return to what consumers perceive as “normal.” - Martin Lindstrom, Neuromarketer)
There are two downsides and one upside to this:
The downside: Indy developers continually discounting their product means they will never be able to get away with selling it at full price after. If they weren't careful with their pricing, ie, the discounted price being below cost (if 'cost' can even easily be determined for a digital copy of a game) they could find themselves in trouble with funding future development.
The upside? Combined with Steam sales for big games, the discounted prices are going to devalue PC Games as a whole. You're going to see many more sales in the future since it's going to be tough to make the same money as they were used to otherwise.
Downside, part two: Publishers that aren't PC exclusive might see this as a liability for producing games for Windows/OSX. Console game sales aren't likely to be affected (or affected very little) by the devaluation of PC game prices. It can be a smaller market, the development is more complicated and the expected price for new games is dropping. The end result is obvious.