Yes, reason being mostly desi families think that it is important only when it comes divorce, which is not true. So they take it as formality.
It wasn’t always like that. UK had visa on-arrival for Pakistani nationals as commonwealth member state. The system was grossly abused (child nationality, NHS, claiming benefits for child etc etc) and then there were other factors too, like economic sanctions etc etc. It’s all changed now and yes one of the parents must be a UK national otherwise child will not get the nationality even if he was born in UK.