Why my query string generates page not found for my view?
Are you using views_data_export? The most likely reason you are getting a 404 (are you sure it's not a 401?) is that your path starts with "/admin" and the menu system may be protecting it because its not sure which view you are loading. 

Also, by default, Commerce rewrites all order and product SQL statements to enforce the permissions system. You can turn off the SQL rewriting if you know what you are doing (this is a security risk).