Really? I cannot recall a single time in all of LOTRO history where either of these two classes were "amongst the least viable", perhaps you could refresh my memory?
Book 12-13 SOA.
In order to better standardize crowd control, our root mechanic was changed from a 4(8 traited) unbreakable effect to 15 second with 75% break on damage (50% traited). Many of the classes other abilities did not function well, if at all. Most of our abilities afforded our target both BPE checks AND resist checks.
Spiders were so bad off that we were singled out by the Monsterplay Developer for a feedback thread which hit something like 25 pages. Jalessa put in NUMEROUS fixes for book 14 SOA:
1. Numerous trait fixes
2. Web The Earth first received it's 10 second slow upon exiting the effected area in this book. OH HOW I MISS THIS. This swung raid fights, and gave us a true role within creep groups.
3. Hatchlings made useful. This was more for small scale fights and soloing, but we finally had a way to hit people with actual damage. When timed properly with our stuns, these things mauled people.
4. Grace Periods added to our Roots. This made them useable.
Really spiders haven't been bad off since then. You could say that late RoR we were a bit meh in organized groups. That was more a problem with Stun Dot and spam cleanse than with our class. Well timed fear, Venomous Haze/WTE on a healing RK on the back line still got things dead though.