This one is a good example (there is also part 2). Terraria is incredibly good game. Actually it's the best game I played in a last year, and I mean all games, not just indies. But. You should be honest to your players and youself, you should not be a pusher. There were, clearly, big possibilities to continue further development of Terraria. But it would be a fake. If developer is making only money on it. I think modern game development suffers pretty much from make money goal. So such an action may seem absolute madness to them. If it was, say, Blizzard, then we would see Terraria 2, 3, World of Terraria etc. But with such pusher behaviour, your game idea, your game world, is on steroids and will always results in unnatural and very predictable games. Starcraft II is an example. It's a very good game, but it doesn't have a soul, it's a pure marketing product. I think large game studios became hostages of themselves, they just can't work another way now, or they will go bankrupt. This is the part there indie studios have major advantage over them. This explains why indie games are so popular lately: they have soul. Like an old games, then there wasn't unstopabble sequels, addons, prequels. There is exception though. Valve managed to fight temptation to make money, and continued to make good games. But that's a personal opinion.
Anyway, there is some very interesting game in develppment now from some other creators of Terraria. It could be a hit, it could be a failure, but I'm most certanly will try it!
Update. An interview with Andrew "Redigit" Spinks the creator of Terraria. I'm glad to find this particular answer which just says that I meant to say, but in some fewer words:
What is your take on the future of indie games vs. the big-name developers?
It’s not my intention to bad mouth the big-name developers, but from my perspective the recent rise of indie gaming is due to big-name developers losing touch with what gamers want. Gaming shouldn’t be treated like a business. If you genuinely enjoy your product, then there is no risk involved because others will as well.
