Because it sounds like exactly what it is - a collection of leftover parts that weren't deemed good enough to be in earlier songs.
this seems to be the biggest reason to not like it and it's legit
I'm glad Northern Lion brought Raw Dog back into the conversation, because after seeing these comments above, it needs to be pointed out that this thinking is not correct. How so?
Yes, the individual parts that make up Raw Dog are apparently leftovers from the BCaSL sessions. However, it is a misnomer to say that they "weren't deemed good enough to be in earlier songs." If those individual parts were not deemed good enough to be in songs, then the guys would not have kept them as part of their "riffentory" list in the first place! The key is, that these individual parts were not used because the guys could not find an appropriate place to use them.
If what you guys are saying is true - that these individual parts weren't good enough, then the same thinking should apply to what ended up becoming I Walk Beside You (mostly written during the ToT sessions) and the riff found at 1:44 in The Glass Prison - originally written during soundcheck on Touring Into Infinity and previously they tried to use it for what became SFaM. You could also say the same thing for the opening bass riff found in S2N, which would've ended up on the cutting room floor if the band didn't decide to push through and write a song specifically using that riff, after having pushed it aside numerous times during the writing sessions for d/t.
So whether you like the song or not, those individual parts of Raw Dog *were* good enough for earlier songs - it was just that they couldn't find the place to use them during the writing sessions for BCaSL.
Which actually brings up a point that I wish would change - the mentality to write just enough for an album. If they have all those free-flowing ideas happening, why not follow their muse and see where it takes them, especially given the short time that it seems to take them to whip out an album's worth of music? That way, they could pick and choose what they feel are the best songs and/or the right vibe for the final album instead of merely going with whatever they came up with this time around. They were forced to do it for FII, and some of their better songs were written because they weren't permitted to go into the studio as soon as they had an album's worth of material. It would also give them material to use as B-sides, soundtracks, etc.