No, I don't think you're being snarky. A measly 5% loss for the overweight or obese is actually quite pathetic, even if the numbers are bigger for someone who is obese than it is for someone who only has a couple of vanity pounds to lose.

What are they looking at sustaining for years - the loss, or the diet? Both? I know of very few people who lost weight on calorie counting/LF who were able to sustain either for years, since special occasions (with the temptation of lots of food) happen several times a year. It's all too easy to go off plan, and gain it all back. Even if you go back on plan and lose it again, that's not sustaining either your loss or your diet. It's regaining the weight you already lost, and starting the diet all over again.

When LC is a way of life, it's easy to sustain both the loss (usually way more than a lousy 5% loss) and the diet.

The only catch is that it needs to be a way of life, not a diet that you go on to lose the weight, then off as soon as you're done losing. If you do that, you'll have the same weight regain results as someone who loses on strict calorie counting/LF, then starts eating normally again.