Look, graphics are expensive. Really expensive. We keep our costs low, and our games thus become profitable quickly. We've had some games that did worse than others, but I've never, in fifteen years, written a game that lost money.
And here's the sad truth. Suppose I spent a bunch of money, busted my hump, and wrote a game with graphics as good as, say, Eschalon. Then people who really care about graphics wouldn't look at my game and go, "Wow! He's really doing good now!" They'd go, "His graphics suck. They haven't improved at all." And then they'd go play Fallout 3.
Don't get me wrong. My next game, Avernum 6, will look much nicer than Geneforge 5. I've been working really hard on it, and there are a lot of improvements there. And the next game after that, which will have an all-new engine, will look even better. And you know something? Everyone will still say they look like crap. Big budget games will ALWAYS look better. I can't compete there, there's no hope, so I don't try very hard.