I haven't seen those discussions, but is it possible that they were trying to rehash the results of Object.hashCode rather than pass all of the bytes of the original value through a new hash algorithm?
Afaik, they augmented the hash function with a random seed, which didn't work out. See: http://emboss.github.io/blog/2012/12/14/breaking-murmur-hash... It appears that SipHash would be enough (for now) to prevent hash poisoning. Most open addressing hash implementations doesn't yet use SipHash though.