I wouldn't say that KDFs used this way is "abuse" any more than hash functions used for secure storage is abuse. It all comes down to what you mean by "hashing".
The problem is that the same word "hashing" is widely used (incl by experts) for 2 different things, normal insecure hashing and cryptographic hashing. As he points out, the 2 have different purposes, ie CRC for large files & git blobs, etc for the first, and cryptographically secure storage of small strings for the 2nd.
KDFs meet all the requirements of cryptographic hashing. Maybe a new term is needed for the process of cryptographic hashing, like "scrambling", or something that suggests secrecy, rather than just generating a unique value.
The problem is that the same word "hashing" is widely used (incl by experts) for 2 different things, normal insecure hashing and cryptographic hashing. As he points out, the 2 have different purposes, ie CRC for large files & git blobs, etc for the first, and cryptographically secure storage of small strings for the 2nd.
KDFs meet all the requirements of cryptographic hashing. Maybe a new term is needed for the process of cryptographic hashing, like "scrambling", or something that suggests secrecy, rather than just generating a unique value.