That doesn't mean that you would have the skills to be able to do a foxtrot or a waltz or a samba or Argentine Tango. It does mean that you have been trained to move about a stage, sing, speak and generally perform like any actor would.
I'm not saying that SCD should outlaw all 'ringers' but at some point everyone will have had some form of performing arts training (actor/singer/comedian) be that on the job training or structured training. It doesn't mean that they can do ballroom or latin dancing.
If we were to ban all ringers, what areas would the 'celebrities' come from?