As a long time FI, the various schools and clubs I've instructed at have all received phone calls from D&D to make practice calls on Fx to help their staff with training. It's use for a position fix for students is paramount, airspace in the UK is complex and the CAA encourage it's use to prevent incursions before they occur. I've encouraged my students to use it sooner rather than later to help, and not to be afraid of using it.
Moody airline crew having their naps interrupted by training is a rather pathetic excuse to disband or ban training on 121.5. What's even worse is morons saying "GUARD, GUARD" on Fx during a call, thankfully only a few times in many years, but I'm sure it will happen again.
So in short, no. Training on 121.5 is required on both ends, and is a very useful tool for both commercial and GA.