The way I see it, the purpose of the Citadel was to band together alliances so that they would be more powerful together. This was so that the participating alliances can ensure prosperity among themselves. A major part of that is keeping that white economic bonus (along with also protecting against exterior threats to the participating alliances). In order to do both of those things, there needs to be a strict policy. Having a policy open to too much interpretation defeats the purpose of the policy. Think of it as a hole in a sock. Once you open up one hole, it easily grows until anything can get through. Infinite exceptions can be made once they start being made. A zero-tolerance policy is, in most cases, the best. And specifically in the context of this issue... An alliance that is confronted diplomatically will still have a chance to simply leave the white color sphere. It's akin to a public property, except there's no trespassing penalty. Anyone can come in as long as they're a citizen but there are police to arrest anyone who isn't. Except this time, you get a chance to simply leave and have no punishment.
Now, none of this is consequential because of the recent leaving of the Council by ESA, but I just want to state my opinion.