Not at all -- in fact there are other free tools for doing what you are suggesting, which are more specifically focused on the task you are asking about -- I just can't remember them off-hand, so i hope others will chime in.
My Find and Run Robot program (FARR), which was suggested above, isn't quite meant for this purpose. However my other program,
Drag and Drop Robot, *was* made specifically to provide a simple GUI for executing commandline apps that you need to run in batch on a large number of target files.
Still, Drag and Drop Robot is not the ideal tool for creating custom GUIs for commandline tools as it doesn't have nice ways to set options, etc.
Again, I know there have been some attempts to make generic front ends for driving commandline tools -- I hope someone will post there experience with those here.