I get the distinct impression from this two part discussion topic that Jim and Bob are having a serious, thoughtful discussion and Yahtzee is just throwing around big, childish blanket statements that need constant addendums to hold up any kind of water.
As the two serious debaters pointed out, sequels can be a great thing, and franchises/sequels are often used--by good developers--to bring around radical new gameplay mechanics but under a market friendly face that minimizes such risk. It's unfortunate that it needs to be done, but it's better than the "expansion pack sequels" as Bob says. A whole lot better. Not even on the same level.
As the two serious debaters pointed out, sequels can be a great thing, and franchises/sequels are often used--by good developers--to bring around radical new gameplay mechanics but under a market friendly face that minimizes such risk. It's unfortunate that it needs to be done, but it's better than the "expansion pack sequels" as Bob says. A whole lot better. Not even on the same level.