There's no real need to alter the 'Lead Status' field if it's not causing you any issues.
We use Lead Status in the same way you use Prospect Status, but at end end of the day they are just two different naming techniques. The only difference is that someone created it as a custom field in your company's Salesforce instance, where Lead Status is a standard field that comes with Salesforce (if I'm not mistaken).
Hope that helps!