Yes, this is the problem.
But, you can fork it to send an array of files, and the controller will call the uploader for each file (or the model... I even don't remember...lol)
Anyway, look inside your component and reuse the uploader, it is very easy if you code it well, a matter of few lines for dealing the upload.
Then to be able to send an array of files (JForms), this is another story. You can do it in many different maneers.
The more convenient is to create a JDom class and share it here (if you want). Then you will be able to reuse it as your please.
Then create a JForms type, calling the JDom (it will use XML file)
Or... Manually call you JDom class in the template. The XML field will be ignored and replaced. You will use the correct name property for you inputs :
I think something like that :