Hmm, okay you personally don't go to conferences strictly as a journalist. Fair enough. But in this particular case Jake hasn't self assessed himself to be an Ubuntu contributor. So in this particular case, Jake went there primarily as a journalist covering a story.
And indeed having press at an event does add value for the journalist and the organizer and the readership. I would not suggest otherwise. But there are ethical considerations for the industry to consider when journalists are dependent on sponsorships from organizing entities.
I believe it would be adequate disclosure for anyone who attends and event and is sponsored to attend an event should disclose their sponsorship, whether they attended strictly as a contributor to participate or as a journalist to cover the story, or as a mix of both. It is good practice for a number of reason to disclose sponsorship depending on your particular situation as a sponsored individual. The GNOME devs who write personal blogs do a pretty good job consistently tagging GNOME Foundation sponsorships for events they attend and write about for example, though for completely different reasons than the reasons I would expect a journalist to disclose sponsorship to their readership.