Speaking of which, that seems to be the logic here: don't argue against bad music or make the obvious inferences based on the available 240 seconds of material, thus more or less defending that material instead.
I don't get it. Listening to Burzum is never about "that one memorable riff" (otherwise you wouldn't like Hlidskjalf), while the Immolation's song you're referring to was, indeed, a whole song. How can you extrapolate the context in which those 30 seconds are set, which direction that riff is coming from, and where it's going to, considering that the average track length is above 5 minutes?
It's not about "defending" or "bashing", it's about time.
Well, we've heard the intro in full, and it has no reason to exist. We can ignore it because it probably won't have much impact on the album as a whole, but "Sverddans" is about two and a half minutes long, and from the sound of it, isn't going to develop into anything interesting at all. We've heard about a fifth of the song, and there is no real reason for it to do anything else within its particular framework. The rest of the tracks are harder to make statements about, but context isn't everything. Sections of songs often cannot stand on their own without surrounding phrases and logic, but that doesn't mean they'll sound bad when taken out of context; it just means they'll sound uninteresting, or not as interesting as they could. These samples sound bad because they sound illogical, and poor logic cannot be fixed by context.
Finally, out of eight samples, none sound above par. What are the odds that not one of the samples is good, but the album as a whole will be? To think this is worth "reserving judgment" over is to grasp at straws. If ANUS is being biased about this album, I wouldn't know one way or the other, but it does seem as though a lot of people have a sentimental attachment to Burzum, and are scared to say anything bad about its work. Maybe both sides are biased, in which case, only one can be right.