While allowing comments against files under /doc makes life 'easier' for those wanting to comment on docs (!), it could result in those useful comments not being integrated back into the underlying docs for some time. However, without such a facility, those comments may simply stay in the head of whoever is thinking them, which is worse still!
I edited and submitted patches against some of Roberto's docs, a while back, but for some folks, that process would have been "too hard", and they would have given up. The barrier is too high.
So, I'd say that allowing GC-style commenting on docs is likely to be a net gain for the community overall, because it will encourage more people to participate in trying to improve OpenACS. Maybe Roberto (or someone Roberto persuades to do this for him for particular documents or modules?) could try to allocate an evening every month to go through the resulting comments and incorporate them back into the base documentation they refer to?
Can we try it? If in three or four months it is clearly not working (no comments make their way back into the docs, or noone actually
comments anyway!), fine, we'll know we need to find a better way.
But at least we will have tried.