I really don’t have the time to sift through however many X pages of dev responses on this forum or on a certain discord - but I’m more than 100% sure the goal was that every spec should be viable in some way in group content, whether it’s the case a spec is more useful in a 3man than a raid is up for debate, but, the point is it can be used in group content - you only have to look at their class changes over the past 8-10 months to see that that is the direction they’re heading in. Otherwise we would still have yellow minstrel and yellow warden, and yellow guard wouldn’t now also be on the chopping block, as are potentially one of the lines for Hunter and LM; if what you said was correct we wouldn’t be in this situation, but we are, so it remains to be seen that you are incorrect.
https://www.twitch.tv/videos/1586251192?t=16m54s if you want a reference. From what he said, I have always understood it as "a viable role" specifically for instances. They will make sure every class has a viable dps trait line. The other lines will allow you to do "nifty things".