Expression Loopout

You completely misunderstand what those expressions do and what they are for. Rick already has explained the why. The only thing that isn't clear is what you would actually need the loop for since you haven't cared to explain. Depending on the use case your whole approach may not make sense.

Mylenium 

You cannot create a video that will seamlessly loop in a media player. You can create a video with identical first and last frames that you can import into After Effects or other video editing and visual effects apps and interpret the footage to loop. In After Effects, select the footage in the Project panel and go to the File/Interpret Footage menu to set up loops. 

Media players always pause for a moment or two when you set them to loop, so seamless loops that will play in a standard media player are not possible.