The problem with celeb kids is that they are compared to their parents, and they can never live up to it.I think the kids really aren't attractive at all. They are also thick and will reply on their parents for money for the whole of their lives. Total wastes of space. Perhaps Harper can be saved if they stay in one place long enough.
It's the same with the Beckham kids. If they were your neighbour's kids, you would never, ever describe them as unattractive, because they are objectively not. They are just not as attractive as their parents were in their heydays - and at least part of that attraction was from fame and hype. I would say that Romeo and Harper are good looking, and Cruz and Brooklyn are perfectly normal.
As for thick and wastes of space, that's really harsh. They are so young and two of them are literally children, and you don't even know them enough to know their cognitive abilities. They have plenty of time to make something of themselves and discover their talents, which likely lie outside of sport and showbiz.