That's not shallow at all. If a job doesn't list an attractive salary it's a clear indication it's not a good job.
Some firms won't list it also for legal concerns as well.
There are two types engagements recruiting firms have with companies:
1. contingency - You only make money when you place someone. This is what triggers the blasting of many resumes over to companies with little vetting. In short, it's a numbers game.
2. retained - This is when a firm pays the recruiter either all or partially upfront. The recruiter is then incentive to their very best to place the candidate.
When you really dig into the recruiting space, it's very interesting and you start to uncover things that create a bad experience for candidates, companies, and recruiters.
Or I'll ask former employees sourced from their Linkedin profiles. Fight information asymmetry whenever possible.
Sadly there is not much of an appetite for truth that affects any business exploits that rely on misinformation.
If you began informing Ethiopian coffee bean farmers of how much Starbucks charges for a cup of coffee for just a few cents worth of coffee beans...
They would find a way to raise their price ;)