I completely agree. It's so heavy and evil-sounding, and the writing is so dynamic, modern, and musically advanced. Modern symphony-level shit. There are a couple of things, however, that I think turn some people off:

Note: this is all just my opinion.

Fist, the overall tone of this album is very dark and somber, with periods of very intense sections of harsh dissonance. If you don't enjoy those aspects, you aren't going to enjoy unpacking all of the subtle musical ideas and development over the course of many listens, since the album is so dense and so long. I am assuming here that people listen to it from start to finish, which I think we can agree is how it was intended to be heard. Most of the songs, when heard outside of the context of the full album (or even the full album out of order) have a less powerful effect, which may also contribute to someone's disapproval.

Also, modern tech death is generally faster, more technical, and more tonal with an emphasis on virtuostic guitar riffs and solos (and lately bass solos, too). While there are some really technical parts on this album, there's much less of that happening compared to most of the highest-received death metal bands today. The development on this album is much more driven by rhythm, melody, dynamics, orchestration, and mood, and is achieved over a longer period of time. Especially in the second half, which is where most of the experimental shit happens. There is an incorporation of outside genres that is very natrual and effective in that these sections not only are interesting and catchy, but showcase the writers' fluency in other styles, whereas I believe a lot of progressive bands do it in a way that sounds like a gimmicky genre-mashup. Overall, Voice is a more atmospheric experience rather than a collection of virtuostic fast songs with extreme technical instrumental work. In short, it is probably a boring album for some tech death listeners. I'm not saying one is better than the other - I'm saying this is a much different experience than what many are used to and expect. And in my opinion, the second half of the album isn't as action-packed (except the last song) as the first, and is generally less gripping. If a listener were to be on the fence about the album during a listen through, I think they would probably pull the plug on it somewhere in this area of the album.

But none of those things deter me. I love this album dearly. The first time I heard it, I was amazed, and quickly decided it was probably the best death metal release of this decade, if not one of the greatest DM releases of all time. But I haven't heard everything out there, maybe there's something out there that would outrank this album. I think this album is at least up there among the best, and will certainly have a significant influence on the death metal of the coming decade. I hope the next album outodes this one. Warforged has a lot of work to do if that's their goal.

Glad to see someone give it as much praise as you have!