hairymclary if they were, as the article suggests, on their way down from having climbed it when they got lost (not uncommon on Scafell if I recall correctly it can be hard to find the right path down) then presumably they were intending to climb the whole thing (unless they were extra-specially clueless and managed to climb Scafell accidentally, in which case hats off to them).
Climbing/hiking with children is a good thing. I'd see nothing wrong with going up Catbells with a 5yo, even in February (except that the sheep would probably eat your lunch). Nothing wrong with a walk around the lower reaches of Scafell either, assuming you know where you are and what you are doing. But climbing to the top and back, in February, starting at midday? I can't see how, with a five-year-old, you could hope to make it back down again in daylight. And Scafell is bloody tricky in the dark.