I think that belgian candi sugar makes for a good compromise between the two camps (dry vs. Crystal). Since you are already probably going into the 40 SRM range using a super dark candi sugar will give some unfermentable sugars that leave some dark fruit and caramel character without being sweet and overpowering.
After trying a dark homemade candi sugar and some special B in a black IPA the beer turned into a RIS after a couple months when the hops started to drop. The "no crystal malt" crowd is giving the advice because of the danger of the beer becoming an American Stout or a hoppy stout in general. The "dry it out with sugar" crowd is advising this because a sticky black IPA is really unenjoyable. High mash temp, belgian candi sugar and good attenuation I think gives a good balance(just my personal experiences with the style) you still get the high hop character with some of the roasty chocolate coffee malt character, easy to drink and refreshing.
My personal experience with brewing the style I don't think Crystal malt is necessary when you use a good malty base malt (I like an American Pale Ale malt), mash high, some dark candi sugar and some basic cane sugar to help lower the overall final gravity, and a good pitch of a yeast with decent attenuation character gets a good black IPA.
It's a tough style and everyone's got an opinion. Too much body you have a hoppy stout. Too much roast and you are drinking an ash tray. Too sweet and you have a sticky bitter mess. Not enough hops and low roast you have a bland American stout. I brewed almost 25 recipes of just off the cuff writing my own recipes that were 1/3rd crap, 1/3rd meh, and 1/3rd "hey that's almost decent", I've had more fun coming up with my own recipes and making mistakes because I wrote all those recipes myself and learned a TON about recipe formulation and about my own personal tastes.
So when I say it's just my opinion, it's just that. Everyone else is similar (unless they're posting an award winning recipe. We are posting our opinions and interpretations, and personal tastes, about the black IPA style. So in the end brew what you want, it'll still be beer and will probably still be delicious (or at least get you drunk).
I interpret the style as a midway between an American IPA and a Double IPA in terms of ABV and IBU/hop character, then you add roasted malts for coffee/bittersweet chocolate/dry roastiness on top. Make your beer and taste it when it's done, tastes more like a stout call it a stout, or call it whatever you want if you are just brewing for yourself.