To get by in the multirole the Reliant is slated for, it needs to be able to run, hide or fight. Any one of the three will do, but it can't do any of these. No one wants a ship with no defensive capability, so CIG needs to do something with it. As is, the Avenger outperforms it in every way, so why would anyone want one?
Now if they kept it slow and clumsey, and undergunned, and fragile, but gave it pipes for all sorts of different customization, even making the small cargo area avalable for special scan packages and such, and then gave it really good range and stealth. . .THAT would be cool.