"The truth is, if you are a woman, and someone threatens to murder you online, it's overwhelmingly likely that no help is coming, and you're on your own."
And as a woman, that's her view, but in reality if you're anyone (who isn't rich and famous, but even then) getting threatened online... it's going to take a *lot* before the police step in. There are many reasons for this, including
a) People say stupid shit online, there's lots of noise, and it's not easy to decipher intent. Similarly, if somebody threats you on the street it may not get much action, unless it's a public action with something backing it.
b) If your neighbour threatens you, the police can go over to his/her house and deal with it. When it's online, that person isn't likely using a real-name, and may not be anywhere in your jurisdiction or even country/continent
c) There's often a prevaling lack of understanding of technology in the justice system
d) Laziness or resourcing... due to (c) and (b)... it's work and resources to actually catch somebody and then sometimes even harder to convict. Again, hard to condone, but unless we want to wiretap everyone (well, they tried) or spend a month of work of three officers in order to track it down... sometimes things need a critical mass before they'll dedicate the effort.
None of the above are excusing the aholes that post terrible crap online, especially death threats, but saying that it's exclusively a problem of a certain group - whether it be based on gender, ethnicity, or other - is not particular accurate.
Of course, society is wonderfully unbalanced about such things. Sometimes nailing somebody for what is obviously a joke, particularly if the target is a rich scientologist like Tom Cruise