BabyGanoush, in children without any extra needs (which could be disability or a very chaotic homelife or medical reasons, or undiagnosed as yet additional needs) there may be a tendency towards toilet training at a later age than our predecessors. The general view being that child led,might be better for the child than the parent trying to introduce it at a time when the child isn't ready.
I toilet trained my dd1 at 3.2 (I think around 3 is the norm now), we had had several attempts where she clearly wasn't ready, and then when she was 3.2 it was sorted over a week.
Does anyone really think this is a problem? For children to toilet train when they are physically, emotionally and cognitively ready? Surely not.
What the article and op is saying is not this however, what they are saying is that there are a whole crowd of middle class feckless mothers who are too lazy and distracted to toilet train their own child, not taking into account that there may be many reason (as listed above) why a child may e in nappies later.
The article then goes on to talk about,what I can only assume are a bunch of made up lies and examples,where 5 or 6 children in a class are in nappies due to their mother's crapness.