Well, to start, a bagel with 25 g of carbs would be at least 2 points as
each carb gram is 4 cals, so there's at least 100 cals in the bagel, and
that's if the only cals are from carbs.

WW is basically just calorie counting made easy, you eat within a calorie
range each day that leaves you with a calorie deficit at the end of the day,
so fat is burned to make up the missing calories.  Basically, even if the
carbs are not burned, and they turn to fat, that resulting fat is then
burned up due to the calorie deficit that the person is maintaining.
However, a healthy diet recommends that 1/2 of a persons daily calories come
from carbs.  If someone is going to be eating something that is excessively
high is carbs, it will most likely be high in cals and therefore high in
points.  That way, everything is accounted for.  WW does promote healthy
eating overall, 2 servings of dairy, 5+ of f+v, healthy oils (2 servings per
day) and water.

WW absolutely promotes exercise and there is an allowance made in the plan
for calories burned in exercise.  You earn activity points based on the
intensity of the exercise and your weight, These points can be ate or not as
desired.