Invoking “qtpfsgui --load <filename.hdr>” where <filename.hdr> stands for an existing HDRI file, do nothing, while it probably should open the GUI and display the HDRI image (seems HDRI image can only be opened from the GUI and actually not from an qtpfsgui invocation).
This option is deprecated. In the current version, you need to specify the name of the HDR file and it will be open automatically as soon as the program start. You can as well list a name of LDR files and the wizard for the HDR creation will be automatically open for you as soon as the program starts.