Just that some people want an abstraction isn't a reason to put in List::Util. Feel free to create a module with the abstraction you want and distribute it.
What are legitimate reasons to put it in List::Util?
Having List::Utils, List::MoreUtils, List::EvenMoreUtils, List::SomeMoreUtilsByMe, List::AnotherCoupleUtilsTheyForgot, etc. seems like it might be a Bad Thing. Better to have basic list utilities in one List::Utils module, I think. And the reason they're not included? They're "too basic".
It's a perfectly good reason to include them in List::Util. It's not an absolute mandate that they be included, but it is a reason.
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