In my opinion, I supported Diago back then and didn't see the need to leave an additional comment to show it. 
Here's a related question about the tag that shows how I feel about them: https://meta.superuser.com/questions/1381/banned-tag-proposal-hackintosh 

The reason I would refrain from making it official is that its not a big problem, we can deal with it on a case-by-case basis. If we had to add a bullet point to our FAQ for every single instance of something violating our 'FAQ' or community policies, the list would become way too long. 

We didn't put Synergy questions in our FAQ, even though it was made clear to them, we didn't want to be their exclusive support site (as much as I disagree with that).

While it may be a weak excuse, another important reason its not in the FAQ is that I don't see the need for a witch hunt on these questions. If I spot one, I'll deal with it, if it manages to fly under the radar, well good for him. The community can only do so much and I've never seen the need to hardcode the policy somewhere