There really isn't anything wrong with pointing out 1) how unlikely something is to be added.. at least anytime soon, and 2) that is is probably going to take considerable work to accomplish.
Obviously, if there is no evidence to support the claims, then you shouldn't just guess. Or at the very least, you should state that it's a pure guess. But there is ample evidence to show that the channel windows are text based and that any additional controls or graphics is not a current feature. And from a programming standpoint, changing a text-only control to also include graphics or trees (what this feature would use) is not just "flipping a switch."
When people ask for a feature that has over an extremely high chance to require a lot of work, then it's better to tell them that right from the start. It lets them know that it probably won't happen anytime soon and may not happen at all. If something will be easy to implement, then telling them that gives them hope that it could be seen in the next version or two. Khaled doesn't typically reply to feature requests except on rare occasions when he says it will be in the next version. Most people like to at least have an idea if it's likely to happen and if it's likely to happen soon. Yes, people don't like hearing "no" and they don't like people disagreeing with their suggestions, but the world is not about puffing up people's egos by always saying "yes" or agreeing with them. Disagreeing with something is just as valuable as agreeing with it.
