There is the distinct possibility that the site you link to uses a streaming technology not recognized as a 'MultiMedia URL' by the software you use. At least, that would be my first guess.
Protocols have a way of coming up and dying down. Because trying to improve an already existing protocol is more often than not a lot harder than making something new. That and the technical debt that comes with already existing software of any kind, sure makes it an easy decision to make something anew.