Okay, I haven't seen an entire Katharine Hepburn movie, but I've seen enough to know there's some element of likeability there that's totally absent from Cate Blanchett's character. I've also heard from trustworthy [older] sources that it was a crude impersonation.
And the chemistry between her and DiCaprio didn't work for me at all, maybe because they're both doing impersonations of extreme people.