I think WWN gets recommended for the reason you stated; the GM tools are very good. It also, I think has a reputation for being similar enough to 5e that tables accustomed to that might have an easier time switching.
I think skills in general aren't so popular because they place kind of psychological minutes on what a PC can do. If there's no skills, it's easier for players to imagine that they can try anything, even if they aren't necessarily the best suited for it. For example, in a system without skills, a player might just try to intimidate a bandit into running away, even if their Charisma is 7. In a system with skills, they likely have a negative modifier to Intimidate, and so are less likely to try, since someone else likely has a better chance of making it work when the dice come out. In the event that they want to do something that's not on the list in front of them, some number of players will also simply assume they can't do it (it isn't on the list after all).
Personally, I just find them unnecessary. If someone wants to do something that they have the skills and tools for, it just works. If they don't have one of those things, I just ask for a roll of the most relevant attribute.