It can grant grant mana per totem - this is a new change, and maybe other new things are good ways to use the totems. (Eg. they now look quite good at generating mana if you need it).
I’m only talking about using thorn totems as poison damage dealers.
Let’s put hyperbole aside and look at numbers (these all assume using the shaman mastery’s -5 totem mana cost and 10 free attunement. Heaven help you if you want to cast this skill with any other mastery!):
Previous patch I had 5 totems, duration of 12, cost was around 30 mana, I had all the poison and poison duration nodes, and had 3 points left over for 54% more damage and -15% cast speed.
This patch I have the skill at level 18, with 100% chance to poison, it costs 80 mana, and I get 4 totems at the moment. Once I get 5 totems and another mana node it will cost a lot more mana, ( but let’s say 90) and have a duration of 9 seconds.
So in patch 8.0 for gaining 15% poison duration, we lose 54% more damage and -15% cast speed, 3 seconds duration, and the mana cost of the skill looks like tripling.
Or another way to phrase it is we triple the mana cost and lose 4 skill points.
Yet another way to phrase it is we spend 30 passives getting enough attunement (mana) to cast one underwhelming spell every 9 seconds, and still run out of mana after 2 casts.
We can also compare it with the (buffed) storm totem, which I use for fun as a poisoner. It deals more damage more consistently, has better AOE, better single target, is specced using 15 of its skillpoints on defence and utility, has a 3 second coldown, faster placement speed and costs … 8 mana.
That seems to be a whopping nerfstick for the poor, already underperforming thorn totems whose archetype is meant to be designed for poisoning things.
Now it may be compensated by some increased stats on onehanders, and other things that are, as this thread implies, unfathomable. However my intuition is that the changes were primarily designed to address the lag created by the poison cloud on death node, and while addressing that, they decided to get rid of the cooldown part, so they unthinkingly tacked on some health and the combined result is they genuinely do not realise how much of a nerf they hit it with.
*As an aside, I actually support the idea of changes to the thorn totem tree. I tested the old tree a lot, and there was no incentive to build heatseeking (5 nodes for a dps decrease because the heatseeking AI causes them to fly in circles and not hit things), the reduced arc nodes didn’t work in practice and individually casting them was far inferior to casting the group all at once. So it was definitely a tree due for some buffs, changes or worst case some neutral rework. but not this savagery!