The data mapping is a result of several technical discussions with IceTV, with very strong input from their side. IceTV have been well aware for decades that their data modelling does not reflect how broadcast TV works, but they choose to persist with their own internal scheme and try to map this to various external schemes. I think it is fair to say that the decision is mostly IceTV's.
However, returning back to the mess that SBS have made - I think it is important for consumers to let SBS know that the new EPG descriptions are not acceptable. Best way to do that is for everyone affected to send them an email to tell them that the new data is not wanted in the short description field and should be appended to extended description. It's probably best not to mention any specific brand of device, or if you must, point out that the problem is evident on all brands, not just Beyonwiz. The email address to use is ATS@sbs.com.au