Even if that was fair for a level 1 computer programmer, (which it isn't) - part of your negotiation process is slotting you in to the title that pays what you want;
I currently have the label SysAdmin, but you could easily call me a programmer, a systems engineer or a devops engineer, because my job role includes all those things.
(As an aside, sysadmin is the lowest-paid of all of those titles, which suggests that I could get a raise by finding an employer willing to call my role something more expensive.)
To be honest I haven't heard of H1-B candidates negotiating what the prevailing wage will be on their LCA and I'd be surprised if even a handful of employers negotiated on that. But you made my point for me. Your employer could have put you at the higher pay scale but didn't and in fact put you on the lowest of several options. This is the way the system was designed to work.
I'm not disagreeing with you, I was pointing out that there is a lot of effort put into gaming what exactly "market rate" means for any job. A lot of effort put into preventing workers from knowing what other workers make even outside of any government program; It's an adversarial negotiation.
The rule that H1B workers get paid the prevailing wage is... quite difficult to verify or enforce.
My own (completely anecdotal and subjective) experience is that the H1B workers I've known well enough to exchange salary data were either way better than me technically, or they were getting paid way less than I was. My impression is that foreigners (esp. foreigners from lower cost-of-living countries) get paid less for the same skill.
I currently have the label SysAdmin, but you could easily call me a programmer, a systems engineer or a devops engineer, because my job role includes all those things.
(As an aside, sysadmin is the lowest-paid of all of those titles, which suggests that I could get a raise by finding an employer willing to call my role something more expensive.)