Lauren, you might find that your users can email a person and it doesn't bounce, but that Marketo emails will bounce (for a number of reasons, shared IP, blocked IP by the recipient since it's different from your company IP, etc)... The information might not be correct from their experience, but it is correct from Marketo's experience. Maybe it's just a matter of explaining that this is the Marketo status for emails?
Personally, we find this information to be useful because we send emails that our Account Managers want or need to know if the client received. It's also nice to know if a prospect won't receive our marketing outreach. Additionally, if there are repetitive bounces, maybe it's because the person has left the organization or changed their email. There are a lot of different reasons why an email might bounce (hard or soft). You might review
this thread where I linked to another thread regarding bounce info.