I know this is about UK (where I am a foreigner living for almost a decade).
But why are pretty much all governments universally inept? It's not only the UK but US gov has also pushed for this and plenty of other stupendously stupid ideas or decisions - and plenty of other governments (well, all of them) besides.
It leads me to believe that our species is incapable of leading itself, that we are incapable of choosing good leaders.
When you look at the pay available in the UK government for this kind of work you'd understand. Interns at financial firms get paid more than the most senior technical staff in government.
Look at how these guys are selected:
Democracy: Through popularity contests
Monarchy: Through birth
Other various dictators: Through force/corruption
How on earth does anyone expect the best, most competent people for the job to be selected by these methods?
What makes you think this is ineptitude? They know exactly what they're doing.
The mistake HN commenters make is thinking "But TLS is encryption too! They can't ban Signal without also banning TLS!". They absolutely can if they want to.
The skill set required to reach leadership positions does not necessarily match the skill set of a good leader.