The thing I think you have to understand in order to have any hope in hell of deriving satisfaction from 'White Darkness' is that it is, first and foremost, a love letter to the pulps. And when I say pulps, I mean the unreconstructed, practically paleolithic by modern standards pulps. The novel references Lovecraft, World War I Germans and voodoo in a sort of ur-pulp villainous scheme...evil voodoo priests team up with German soldiers to revive C'thulhu. It doesn't get more pulpy than that.
And this is, as often happens with Doctor Who, both a blessing and a curse. It's a blessing because as Paul Magrs famously described it, the TARDIS is really a machine that travels between genres. The Doctor frequently works best when he's bouncing off the well-established tropes of other stories, reacting against them in unexpected ways and making them respond in ways they're not used to. (The crude, but effective example on display here involves the Doctor chasing down the evil bocor Gilles Lemaitre through a network of tunnels...and using a laser cannon to cut shortcuts into the rock so he can get to the villain's destination first.) Plunking the Doctor down into a stew of pulp tropes is a good way of developing an interesting story almost by default.
The curse comes from the fact that those tropes are so old and well-established that they resist that kind of deformation. For all that David McIntee tries to show a more culturally aware and socially responsible view of voudou and Haiti, the old pulp tropes of savages making human sacrifices and dancing under the moonlight to their debauched and foreign gods still come out, simply because McIntee can't wholly let go of them and still create the kind of atmosphere that he's looking for. The most heroic native character is mixed-race, and even though I don't think the intent of it was racist, it's hard not to escape the problematic implications of making the "better" character whiter as well. Deliberately attempting to recreate a racially problematic era, it is hard not to bring the bad along with the good.
And frankly, this kind of subversion works better with a writer whose gifts involve wordplay and humor. You don't get that with McIntee. He's a functional writer whose strengths are plotting and concept, not characterization and wit. Twisting a genre trope on its head doesn't come naturally to him, because he relies on those tropes to sustain his novel when his narrative gifts aren't quite up to the job. (Take Colonel Mortimer, for example, who's basically a stock Marine character from Central Casting there to handle a role McIntee doesn't care to invest more energy into. Or medical examiner Howard Phillips, whose name might as well be Lovecraft P. Pastichey.)
This isn't to say that the novel is bad--only that it aspires to be nostalgic and functional in a range that is rapidly becoming much more. We're still in a period where Virgin is finding its way, and certainly we've already seen much bigger stinkers from the range. 'White Darkness' works as a piece of fiction in a way that say, 'The Pit' utterly doesn't. But at the same time, it's hard to read 'Lucifer Rising' right before this and feel that the two of them belong in the same book line.