Your complaint may not have received a direct answer likely due to staffing constraints, but it DOES matter and kudos to you for submitting it. I am a former Fed (different department), and we absolutely did read public comments carefully. These comments absolutely do affect policymaking / guidance that is produced, and it's usually someone (or a team of someone's) job to aggregate comments, spot trends, and provide data for senior policymakers on public opinion, so every submission that shares your sentiment would add to that data set. Every submission does count, and believe it or not the vast majority of civil service Feds do care about their work and try to represent the public well.
Also, you wouldn't believe the power of a well-written and measured opinion vs. a sloppy, angry, rage-filled one. If you submit a well-reasoned, polite yet firm argument, your submission tends to rise above the pack.
Though naturally I can't speak for every Federal agency having equally dedicated people, my experience was that we were very concerned with public comments and opinions and did our best to determine policymaking based in large part on those very same comments.
Remember, when everyone thinks Feds don't listen and noone speaks out, the few voices that do are the ones that get heard.
Good on you for being one of those voices.