... and what exactly would "a good chunk of the fanbase" be?
Just like every album by every band ever there are people that like it and those that don't but to say "passionately hated" is pretty ridiculous and don't really understand how you can come to that conclusion. I see people love it and hate it, just like usual, but statements like this just don't make any sense... unless you can back it up with a lot of evidence of this "passionate hate" cuz I just don't see it.
I also seem to remember people saying this junk about Falling Into Infinity, which now gets quite a lot of love.
If you don't like it, great, if you like it, great, but it's generally the people that don't like something that tend to make the wildest claims and exaggerations and so have the loudest voices trying to convince people to also share their opinion but for what? Why tell your buddy to stay away when they may end up enjoying it? That does nothing but hurt the music.
Well, I've been around for a few album cycles now, and the reactions The Astonishing gets, even so long after its release is definitely not the usual "some love it, some hate it." It's a polarising album, which incites unusual passion in both the "love" and the "hate" camps. You wouldn't find such FB posts (with that many likes - 3,5K now) like the one I linked to about any other DT album. This sentiment is also echoed on many forums.
A "good chunk" means a noticeable proportion. It's by no means the majority or even close to the majority.
I have 3 friends, who are lifelong, really hardcore DT-fans, and none of them liked the album, at all. They don't know each other, they all came to this conclusion independently. It's anecdotal, inconclusive evidence, but knowing them, and knowing what they each like about DT, it's very telling for me.
Also, the Astonishing tour was a flop. There may have been other factos at play, but I can't help but chalk some of it up to the album itself.
As I was typing my original comment, FII came to my mind as well, but I get the impression that, in retrospect, most people seem to really like it (one of the most often cited positive opinions regarding Sons of Apollo is that it echoes FII). Remains to be seen how TA will be regarded in the more distant future.
Your last paragraph is completely misdirected, I couldn't care less about trying to "convince" anyone about liking or not linking anything, that would be just silly and childish. I just expressed what I perceived. If anything, I hope that more and more people like it, and it has commercial success, so DT will go on making music for long.