Several possible reasons.
1. They're not actively malicious and have the emotional capacity to feel embarrassed
2. They know they were talking about her voice and making comparisons and that this is A Bad Look and they've had a terrible week PR-wise already
3. Might be a trademark violation, I'm not sure how that law works (in general let alone voice) but there's a reason why Pear Computer had to change their logo
#3 famous people do seem to have some control over their likeness; I don't know how real that control is or anything about how it works, just that it looks like this from the outside. IANAL, so treat that as a claim of analogy not literal.