Yes, many of us are unhappy about the state of the yellow line. Personally, I think that what needs most work is the capstone skill "The Ancient Master" and the last set bonus "Force of will". However, I would like to point out that it really isn't fair to compare the numbers we got on our debuffs in yellow line before to our numbers now. This is because now the yellow line is a support line, which involves not only debuffs and cc (as it did before), but also healing. This was, in my opinion, a good change; we now have a support line (yellow) and the blue line is free to be completely pet-centric. This doesn't mean I believe yellow to be fine as it is, I just think one should take into consideration the trade-off that is happening: we lost in debuffs but gained in heals.
Also, regarding some potential bugs I believe to have found in the yellow line, see my latest post in this thread https://www.lotro.com/forums/showthr...e-class-is-now