It is up to you, the fans, buyers and users, to decide which way the gaming industry will take.
I will come up with an example of bad reputation caused by NOT fixing a product because the successor game was already in developement:
Medieval: Total War
and its add-on Viking Invasion
Great games. But VI was flawed, had some new features, but terrible bugs, too.
Only after people at a huge fan site protested, wrote to EA "we will not buy Rome: Total War if this is not fixed!" they reacted reluctantly - mainly because of getting perhaps a NEGATIVE image, see what SirPleb said to this topic.
They made a patch that left still several issues open. The most game-breaking were fixed however.
Reminds me of a company that has of course better support, Firaxis, but now leaves probably Conquests with broken submarines, Armies... see above what bugs still exist.
If Firaxis does not fix those bugs, I consider them not gamebreaking, but MAJOR bugs (submarine), I will wait for Civ 4 - in the bargain-bin. By then they will have fixed Civ4 perhaps at least mediocre and it will not cost too much.
I am not keen on supporting the idea of leaving products unfinished business! Accepting this policy will lead to more bugs in the initial release and no reasonable fixing after release.
The gaming industry must get told that this is not acceptable - by not selling their products. People are also more likely to download games illegally that they do not consider to be of real quality. Sound support, a good final patch after some time, that is a perfect reason to buy a game. Position yourself by quality!
Finally, after so many years of Civ3, PtW, C3C, I think it is a humble request to ask for a good final patch... do not mess with your true supporters, Firaxis!