Edit: For the record, I think having a discussion around how his content negatively impacts the culture online and works for the far right is a valid discussion and view to have. I just think it's going a bit far to be certain in any way that he is a consciously active part of their movement or "group-thinking".
I mean that people seem to think too much about who subs to who on twitter or youtube. It can be done over one interesting video and then forgotten. I also mean that people who are influenced by the mainstream media will have a construed dislike for most things on youtube as a platform due to the many hit-pieces that have been done in the past. Mainstream media lose out on ad-revenue to "influencers" and a platform they have to share with random asshats who will call them out when they make a mistake. Naturally media will blow up anything negative in order to deal with their competition (whether they are quality or not, they are used as sources to navigate the different stances news channels take).
People also seem to think youtubers don't do anything (overstatement, naturally) good, because it's not really reported on.
Youtube, the internet and especially the meme-culture has it's own language of what is serious & what is a joke. While I'm not one who understands it well myself, it's quite simply not logical to take a entertainer who use childish humor like Pewdiepie/Felix & put him or others like him on the same pedestal as 4-chan or 8-chan simply because they have parts of their humor or style of humor overlapping.
Felix for example, from the little I've known, has had both fair criticism (n-word on stream, which he did not try to defend and told the fans who defended him to stop as he was in the wrong & more stupid shit he has done) & unfair criticism/hit pieces (vox & wallstreet journal has been part of it from my memory).
The sub2pewdiepie meme or whatever we can call it wasn't started by him, but his community when they noticed that T-Series would take over as the biggest channel, and he ran with it because they found it fun. The maniac in New Zealand using it to "poke fun" is just another troll from a horrible human being with insane views. Felix cannot be held responsible for that, it would be like blaming God for crusaders or terrorists claiming to do shit in God's name, or telling actual muslims or christians that because things were done "in gods name" that was horrible and that they believe in god that they share the blame and responsibility.
Felix has gone out and told his fans time and time again in videos that he does not want them to hack things or do extreme things like carve in sub2pewdiepie into a building. He knows he will get flack for it, but beyond that he cannot micromanage his fanbase.
The manifesto from the guy in New Zealand was also, from what I've read through others comments (as in, I've not read the text myself) is reported as heavily diluted with meme/jokes/sarcasm and needs someone who has a lot of experience with the different stories to discern what should be overlooked as rambling for the sake of rambling and what should be seen as the guys actual views and reasonings.
As mentioned before, I don't really get these things myself, but from my perspective there seems to be those who are in it, those who understand it's there and don't get it and those who don't get it and take it all seriously. Sorry if this ended up being explained badly, my mind is not exactly doing well these days in getting things properly put forward. I hope it answers your question in a way that you at least can understand where my point is.