Great observation and question.
It comes down to distance and situation.
The pivot/ slash hook kick can be used when shifting or changing positions a quarter turn and only as an opening technique. The threat approaches and you’re attention is elsewhere, you move and strike.
The other situation is 3rd party when the threat’s attention is somewhere else. Then you can really hit them with whatever you want
Oh and feel free to “scrap it”. There are definitely a plethora of other techniques to do.
Some people like it, others don’t – personally I don’t like it either but what I don’t feel 100% on, others do – that’s why it’s in there.