I think the term 'scorched earth' is a tad over the top!
I mean let's face it, Civ III will be seven years old at the end of this year. Just how long do you think developers are morally obliged to support their games? Also, what is so badly wrong with either game that you think they need a final patch? Or, is it simply the case that a 'final patch' for both games would bring you personally, some form of closure?
I don´t think the term 'scorched earth' is over the top. Imagine in your Civ Rev if a ship of a friendly civ contacts one of your submarines you always fall in war with that civ what ruins all your diplomatic gameplay. The same for all AI civs.
Imagine in your Civ Rev there should be advertised armies as units that can load other units and there are wonders that enlarge the loading capacity but the AI doesn´t load two or more units in these armies.
Imagine in your Civ Rev you were advertised that you have a scientific great leader who causes a golden scientific age with boosted science, but the golden age of science doesn´t work and in the last version of the editor even the Scientific Great leader isn´t working too. Former possibilities for great leaders in rushbuilding are gone too.
Imagine in your Civ Rev you would have an option for looking at your growing cities with all wonders and improvements that were built in that city. In the last semi-patch this and the palace-view, where your citizens built a special palace for praising a good leader of their civ was closed for all scenarios because it didn´t stand high enough on the priority list for the last semi-patch.
Imagine for your Civ Rev there would be advertized working land artillery to bring down the defence of a city but the AI isn´t using it.
There are tons of other bugs that were never fixed, so Firaxis was told about them years ago. If you are really interested in these bugs you can get links to the still existing bugs for Civ 3 and Civ 4.
To leave a game with a not working AI landartillery (catapults, cannons, etc.), submarines that can´t be used as they should, armies that don´t work as they should, and, and, and... I think that´s a lot for such a game.
Your question how long developers are morally obliged to support their games is wrong in my eyes. Especially if they ignore these fixes consequently from the first day of the release of the game. Do you really think, that if a developer ignores the proper demands of his customers consequently long enough, he is loosing his moralic duty to fix these bugs?? Do you really think, that if you are saying for Civ Rev to the developer: "The catapults in that game for the AI are not working, the AI cannons are not working, the subs cannot be used as they should, the armies are not working (and so on) and you got no answer and this from the first day on until now and the developer doesn´t do anything to fix this (even not in lots of years), this creates confidence in his products?
And now back to the "scorched earth":
-Firaxis and Take 2 ignored all demands for getting a working Civ 3 game as it should be. And this for years now.
- Even when the fans of Civ 3 said, that they would pay such a patch (what would be a moralic duty for Firaxis and Take 2 to give this patch for free as it only fixes their not-working game-features), there was no positive response until now.
-Even when some programmers among these fans of Civ 3 said, that they would try to fix these bugs themselves when they can work on these bugs with the source code, and the progamming wouldn´t cost them anything, there was no positive response until now.
The real question should be: Can such developers still be trusted that always ignore the demands of their customers in such a way as Firaxis and Take 2 did this in the past?