Bureaucracy gone mad. Do they have separate centers for predicting really bad weather & really nice weather?
You're referring to the fact that it's specifically for medium-range predictions? Well, medium-range is probably both really hard
and where you have the most benefit to life safety and economic impact. If a hurricane is going to hit, you need to provide several days' warning, so that people can prepare or evacuate. Just 24 or even 48 hours isn't enough notice. It therefore makes sense that they'd want to invest significant resources specifically focused on
that problem.
Long-range is harder to do with good accuracy, and perhaps gets more into the realm of climate modelling. I can understand why one might not put the same level of investment into it. Farmers, ski resort operators, and water system managers might really care, but it wouldn't have the same importance to society. It will never have the level of accuracy that's required for planning around heatwaves and major storms.