Without getting into the politics of who may favor or snipe at what shops, I think Maracaibo can be relatively easy or hard, depending much on how the dive is led.
We've done Maracaibo with two different shops, and they were two totally different experiences. The first time, we had been with a shop for several days (our only trip with them) but found ourselves on a boat with a DM and divers we had not yet been out with. The other divers were gung ho to do Maracaibo. We dropped to about 150-160, the top of the reef, took a quick look (no sharks) and spent the rest of the dive drifting through the blue. It wasn't great, and I wouldn't think it appropriate for anyone with only a few dives or who was otherwise having any issues.
The second time we did Maracaibo, we were with Aldora, and they said they had a better way of doing the dive. We dropped by the arch and worked our way to the shallows, which were beautiful. It was a good dive, and ultimately hardly any deeper than a lot of other first dives, and less swift than some. We had a slightly less experienced diver on board. He was fit and calm, and other than not being the lightest breather among us, he was fine. And, of course, the tanks are enormous. I'm not here as an Aldora cheerleader--but huge props to DM Edgar for creating that fine dive.
We'll be back with our most frequented shop next trip. They've never taken us to Maracaibo, and it's fine if they never do, though I'm glad I've done it, especially since Aldora redeemed it for us.
I think those published dive guides have been using the same site descriptions for years. It's possible that few had yet found ways of doing Maracaibo without quite so much depth and exposure (and 80cf tanks). Done the second way, it's probably still an "advanced" site, but it doesn't feel like you're doing something potentially borderline stupid. I still can't see it being anyone's first-dive-of-the-trip site, though.