DLNA is widely despised for the same reasons that all DRM-crippled products are always despised.I question how despised DLNA really is, as I believe you might be letting your personal prejudices get in the way.
Non-techies (and plenty of techies, including myself) just don't care as long as a given solution works, and the DLNA solution is pretty hard to beat:
Plug in your TV, connect it to the network, and click on a video on your laptop to watch.
Out of interest, what kind of open source solution do you envisage when you say that "DLNA will die an instant and painful death the moment a truly open solution is adopted"?
Would it involve hardware, or something installed on the TV, or something else entirely?
All Apple products are, similarly, not supported.
FYI, my iPhone and iPad work just fine with it.