Yes it is confusing and you will hear wildly differing opinions from Drs, dieticians and people alike.
From what I've gathered on my own:
What it boils down to is that fat isn't necessarily bad for you. It's fat combined with refined carbohydrates that lead to all the problems such as obesity, heart disease etc. A while ago there was a theory that fat caused all this (and is still parroted to this day), so since diabetics suffered from heart problems etc the idea was to get energy from mainly carbs and limit fats.
The problem is that this "fat-causes-problems" theory was never proven, and you will find many studies indicating that low carb-high fat diets actually reduce chlo, heart disease and the rest.
Why this is relevant to diabetics is that carbs cause massive spikes in Blood Sugar levels that insulin just can't adequately cover, which is when problems start to set in. So what a lot of people do here is eat very little carbs and get their energy from the other two sources: fat and protein. (these dont affect insulin levels nearly as much)
And also because you are eating less carbs, you insulin intake will be less, so if you do mess up its only be very little and in general you will need less insulin to correct highs, and I found hypos easier to deal with too.
Of course, this is against the grain thinking at the minute unfortunately, although people are starting to take notice. It is not the only method of controlling diabetes, you may have success with a low-gi diet, but I can tell after 16 years of Type 1 rollercoaster-high-carb diets, it never worked for me and Im glad to find the low carb method.
Best of luck to you