Does he or anyone else think that those parents are listening to this speech thinking "Oh right, oops, better get a move on then hadn't I" ?
Parents who can't be bothered to parent don't think like that, do they? They are probably more interested in whatever the latest tiktok trend is or where to get their next fix. Or perhaps they're neck deep in conspiracy theories and poised to distrust anything that comes out of a politician's mouth.
I don't buy this idea that there are swathes of parents who are interested and invested in their children enough to not be total deadbeats but they are lazy and stupid (aka making the wrong choices). It sounds much more like a convenient scapegoat than anything else.
So it just comes across as criticism of parents who are interested and invested but their children have additional needs or other difficulties relating to development, and therefore haven't met milestones for reasons other than parenting (let's remember there are years-long waiting lists for basic interventions like speech therapy FFS) and as OP said, being a parent to a child with developmental issues is brutal in the guilt stakes as it is.
HV check ups have been halved since my eldest was tiny and scrapped altogether in some areas. The UK is already way behind in developmental checks compared to other countries - it's mad. When DS1 was tiny we had a home visit at about 10 days, the 6w check, baby jabs and then a 9m check, a 2 year check and then they had a preschool check. We live in another European country now and there are check ups (outside of jabs/newborn checks) at 6 months, 12 months, and then yearly until age 5.
As far as I am aware the UK doesn't do a preschool or 2 year check up any more. It's one single check at about 10-12 months after the newborn period and then the jabs, which are usually given by a nurse with no medical examination of the baby other than a general are they well enough to be vaccinated. And many of the most vulnerable babies have parents who opt out of vaccinations anyway.
And it sounds to me like the UK is still following a "wait and see" model for developmental interventions rather than the US-style refer anyone with any slight concerns to early intervention and some of the EI children will catch up whereas others will continue to need support longer.
Wait and see is fine if, like what happened with me a couple of weeks ago - I took my 4yo to his check up and said I'm concerned his speech is still not that clear. The doctor agreed and said yes, find him a speech therapist but not before October (October is the fourth "quartile" so starts a new insurance funding block). His first appointment is this week, so we've barely had to wait at all. It means a bit of running around for me to get the insurance slip in time but not a huge issue. I don't actually think DS3 has huge issues with his speech, I don't think he'll need long in speech therapy at all. A bit of a targeted approach which we can follow up at home, and he'll be great.
It doesn't make sense OTOH to have a wait and see approach and then a waiting list of over a year especially for things like speech which can affect their development of other skills like social/emotional/communication. It's completely bonkers. Wait and see plus a prompt response is fine but that doesn't seem to be happening.
If the government are saying we have this huge issue with children being delayed at age 4, does it not also make sense to look at the fact children's developmental checks and support are underfunded to the point of being non-functional?