Discounting goofballs trying to maximize devense for fun and people that want cool looking costumes, it never makes sense to craft any of the hiss,eye or claw cowls. Except maybe the bomb one, if you're a pure bomber but even then MSI+damage high helps bombers more than CTR low+damage low.
Lets work out all of the possible situations here.
A.) I find a book. This means that I will be receiving a black kat cowl, which is almost objectively an upgrade to the other kat cowls due to the nature of their shared defenses.
B.) I fail to find a book. My options are now:
1.) Craft a 5* black kat item
2.) Purchase a black kat hood
To craft a 5* non-black-kat item as opposed to a 4* black kat one: 3 eternal orbs + 400 radiants + extra fetishes
To craft a 4* black kat item: ~5,000 CE to buy into a fight with margrel + a number of tokens.
Would you rather: Find radiants or pay 5,000 energy? And in the end, which would you rather have? A 4* black kat item or a 5* non-black kat item?
The only reason to do either is to save money on finding+using a book.
I don't understand your argument.
First, BKC has significantly worse status penalties than the other kat cowls. So players who need/want defense and don't have money for Punch may regard the other kat cowls as more practical than BKC. I myself certainly prefer BKC, but it's not objectively better.
Second, the other kat cowls can be acquired much more easily than BKC can. All that you require is 200 Ancient Pages, which is not outrageous.
Third, crafting the 4-star Black Kat Mask requires 1 Wicked Whisker. So even the 4-star version is difficult to get.
There is something to be said for the 3-star Black Kat Hood, which costs only 70 Ancient Pages. I would prefer it to the other 5-star kat cowls, but again that will not be true for everybody.
The only reason to do either is to save money on finding+using a book.
Okay, but you're not talking about a small amount of money there. You're talking about "saving" more money than many players ever have. Do I misunderstand your point?