Ofcourse you can critique the encounter all you want!
What triggers some people in this thread (including me) is that you make it sound like the reason you had 30 wipes is because the encounter is buggy. While the orbs is helpful, you don't need them to complete the challenge with leech poison.
I have done a lot of challenges on alts, and Sigryn (as well as Worm challenge) is among the easiest. Additionally, Sigryn is very easy as a rogue because you have a lot of survival tools. That's the reason why it can be completed with around 900 ilvl and random legendarys (but to be fair, most challenges can be completed at 900 ilvl with 1-2 legendarys).
A lot of players in this game has once been raiding hardcore/more serious than they do now - and because they used to be "good", they tell themselves that they still are - but they just don't have the time. The reality is that WoW is a lot about game knowledge and being able to do your rotation, as well as react properly to situations - which all requires you to play extensively. I am a decent WoW player (right now) but that's only because I play an unhealthy amount.
TLDR of this post - the encounter is fine (Not buggy in my opnion), but it is also designed in a way that with 900 ilvl you need to make the dps check as well as surviving, while with 930 ilvl you just need to survive (because your gear negates the dps requirement). This is great, because it means people could get them months ago while it was a challenge for them, and now other players who play less (and therefore has less experience and gear) are starting to be able to do the challenges, while having their entire focus on dodging and doing the mechanics of the encounters. All in all, it creates a sence of satisfaction when you beat it!