Gnostic: I donno, if the pirates cannot play an indie game unless they pay for it, how many pirates will buy said indie game to play it?
Unless it is high quality indie game with AAA quality like D:OS, Wasteland 2, Banner Saga, POE...... then again, one might as well treat these game as AAA games.
Azhdar: Pirates release any kind of games. Warez groups usually target big titles and AAAs. But there are some pirates who release both Indie games and AAAs. The source of those pirated copies can be from anywhere: black market, hacked accounts, free/promo codes, and etc. Also, when someone shares a game on torrent and warez sites, it spreads very fast. Just like plague. 1 working copy is enough to start that nightmare.
What does how pirated games come into being have to do with pirates having a change of heart in buying indie games if they cannot pirate it?
Honorable people will always be honorable as proven by the low low percentage of steam refunds. Dishonorable people, will just move on to a easier target and don't bother paying. If said dishonorable people must fork out money, they will prioritize higher qualities games rather than indie games.
So to the majority of indie games that does not have a great game and word of mouth, it is business as usual.
mechmouse: A pirate free world, will not see the end of micro-payments or day-one DLC or all those other irritations that piracy is blamed for. If anything I'd predict an increase as publishers find a captive market.
If a pirate free world come to being, there is still kickstarter and indie who would steal some share from the publisher by offering non intrusive DRM / DRM free.
The market will balance itself unless customers who don't know better still rain money.
Thankfully GoG already have a catalog of DRM free games that I cannot finish playing in my lifetime that it does not matter if all games released starting tomorrow have abusive DRM.