I think you've put your finger on something important here. From publications and writers of a certain political bent, there is often tut-tutting over why people care so much about the disappearance of a pretty and middle-class 25-year-old white female estate agent, but not about the fate of an unemployed working-class female off a rough council estate who'd vanished (pick your identity politics brownie points).
The answer is that in the latter case, unfortunately, such a person's personal circumstances mean her disappearance is simply a lot less surprising. She's a lot more likely to be living among or - unwittingly perhaps - associate with criminals, notably violent ones.
The reason SJL's case is so absorbing is that at first blush, you can't fathom how she could come to be in danger. White-collar crime exists but it's not often violent crime. It's insider dealing, insurance or mortgage fraud, theft and so on. At second blush, you find that actually some of her behaviours may have been high risk. About 1% of people are psychopaths, so if your work and lifestyle take in a lot of new people, that is a risk you run.
A female friend of mine - with whom I have lost touch - had slept with 20 men by the time she was 19 and at least 100 by the time she was 25; by 30, she thought it might be 300 or so. There was no sign of this changing at 30; she probably hit 500. She was pretty, personable and very approachable. I put it to her that if it were 300 there must have been about 3 psychopaths among them, to which her reply was, I wonder which they were?
SJL need not have had 300 lovers - AS pooh-poohed rumours of 50 - but the nature of her work perhaps meant she met hundreds of people a year and was unwittingly exposed to risk levels we don't associate with middle-class 25-year-old white