And to me, by that quote, that it was to also help those that had never healed before at all and could go in and learn without having to do so in a dungeon. Or a tank to do the same thing. If one always heals or one always dps's and knows their class, how is this going to teach them much of anything new?
For people who are doing well, it won't teach them anything, but as it only takes 10m or so, it won't harm them either. For people not doing well or who don't do extremely basic things right, then it can very well help them before they participate in group content.
Same source you have. Opinion.
I didn't present any opinion as fact. You did. So source it or withdraw it.