Is that what your religion says? It's not the first time I've seen someone from your religion saying that something needs to change.

Well, from my perspective (single player only) I would answer "yes and no": - Yes: it would have quite some historical references. The resources would go back to gaia. - No: - This would leave no choice to the besieged player wiht a single CC to recover eventually and counter attack.  Also, resources are with the player and not with the building. So, if the besieged player has multiple CC and only one is under siege should he also loose resources? I believe no. We do have a gradual change of ownership of any building that is under siege (surrounded by troops if you tell them to capture instead of destroying it). I believe this models more or less what you had in mind, but nothing happens to the besieged player's resources though. So  - again - from my personal perspective, I regret, but would not be in favour of that proposal.

Indeed, the community is too MP oriented (many times at its own peril) for something like this to fly, and in this case, it's actually understandable. The only way I see this working is for people not to care about wining but ranking, and getting more points when wining with weaker civs, but I just don't see it happening.

Not true. I (and most here are surely better than me) have no problems beating an Aggressive Very Hard AI, and I almost always do it only with infantry, which shows the harder levels need to be even harder. The only problem I've seen is that the easy levels are too hard for newbies.