Not just the plug in the back that can cause problems, there's a lot of things that can be just as disasterous flying FPV, having a flight controller that is RTH capable can be a huge asset. My QAV500 is one of the quads that I use the GoPro to fly by, on one flight I was about a half mile out roughly 20 to 30 feet off the deck and absolutely beyond LOS when the video signal went dead due to a fractured wire into the vtx. Being able to flip that switch and have it automatically fly itself back was not only a huge relief but probably saved me a search and recovery mission and resultant crash repair.
You have to weight the risks of the setup you're planning to use and decide if you're willing to accept those risks, I don't know of any system that is 100% failure free 100% of the time so I like having the failsafe of RTH, its already proved its worth to me.
Ken