I know that everyone is different and responds to carbs and insulin differently, but I do not believe that low carb is a necessity for those with type 1.
I was diagnosed with type 1 about 3 years ago and my A!c's have been right around 5 since a few months after diagnosis. Since that time, they have ranged between 4.8 and 5.2 and I do not eat even close to low carb at all.
I am not a big eater, but I do pretty much eat whatever I want and that includes sweets, cereal, bread, pasta, potatoes and all the other things some people say those with diabetes should not eat.
Even with eating all those things, my blood sugar level is rarely above 100 when I test and I test a lot. I strive for my level to be between 70 and 100, preferably below 90, and I am in that range most of the time.
Going by my A1c and the fact that I spend most of the time well under 100, I am sure that I am above 100 for a while after a lot of meals, but I am rarely above 100 two hours after eating. I do not test after eating until it has been two hours as I don't care what happens during that time as long as I am at a level that is good for me two hours after and stay that way even after the insulin has worn off. A good level for me is well under 100.
I think the keys to someone who has type 1 having good control is using the right amount of insulin for both their basal and for what they eat, regardless of how many carbs they eat, testing a lot and being willing to do slight corrections any time they are higher than they would like to be.
Part of using the right amount of insulin for what I eat is using it at the right time. Different foods require different dosing schedules. Often times, in addition to bolusing right before I eat, and once in a while pre-bolusing, I do an addtional bolus part way through the meal and/or at the end of the meal. In addition to that, depending on what I eat, I often do a small bolus quite a while after eating to keep from going higher than I like later from the protein and fats.
For a lot of people, as long as their basal is correct and they are willing to do the insulin and figure out the proper insulin schedule for what they eat, there is no reason to restrict carbs at all.
Shortly after I was diagnosed, I asked my endo how many carbs I should eat and he said the same amount as those without diabetes, just be sure to do the right amount of insulin for what I eat, so that is what I do and it has worked out for me.
I do realize this might not work for everyone, but I don't agree that everyone, or even most people, with type 1 needs to eat a low carb diet.
Should people choose to eat low carb, for whatever reason, whether they find it easier to handle their blood sugar levels, or they want to use less insulin, or they just want to eat what they consider to be healthier, that is great too, but in my opinion, one should not have to eat low carb just because they are type 1.