I really like this album, yet I do recognize it is somewhat less easy to swallow than their earlier work, and consequently might be a less pleasant listening experience for some people. Imho there are two main causes for this.
First cause: its moods often differ, subtly of less subtly, from earlier of Boc's works. There is plenty of suspense and darkness in their earlier work, but this one adds a sense of paranoia and desparateness to the spectre. This might make it a less pleasant listening experience to some people. This time there is no escape.
Second cause: in spite of the many great ideas that this albums carries - some of its tracks will be ranking amongst Boc's finest after the album has lost its 'newness' - it also contains tracks that are good yet imho feel like they should have been worked out better, or feel too polished, or maybe even like a manierism. Obvious examples of this are
Telepath (a track I definitely like, and will be including on many compilations yet to come, yet at the same time seems a bit underachieving for BoC) and
Uritual (not really unpleasant to listen to - within the context of this concept album - but , well, not really very interesting). These are two short intermezzo pieces, but in a more subtle way this 'underachievingness' is present in more tracks, yet less obvious. It is not unlikely that it has been a deliberate artistic choice made by BoC, a style feature to achieve that desperateness I mentioned under cause 1 - and in no way does this 'underachievingness' affect the flow or the concept of the album - but it still might be why some people are a bit disappointed.
Anyway this is just my attempt to profile the dislikers; take it or leave it
The only track I personally have some problems with is
New Seeds: I don't like the intro and what happens to the melody at and after 3:57.
Although not a follower of Nosnam Selrahc, he was a devoted family member.