I'm lucky enough to see this argument from both side.
I occasionally partake in representative competitive sports for the RAF but can see how the fat bloaters in the RAF who can't seem to lift their own bodyweight let alone do anything sweat inducing (and I don't mean contemplating a salad instead of chips) could be annoyed by someone who can actually pass the p!ss easy RAF AFT getting time away from the workplace to pursue an outside interest.
Of course there's also the F6000 to consider. As someone who doesn't like to shout about any charity work I do or take up pointless secondary duties such as deputy to the deputy SIF rep I need to do something to level the playing field and if it can be something I enjoy doing why the hell not.
Perhaps rather than moaning about folk who do sports getting promoted for their sporting prowess perhaps you should be moaning about a promotion system that seems to promote on everything but an ability to do the job one is paid to do.