That is one of the conclusions of Neil Thurman, of the City University, London in an article entitled Forums for citizen journalists? Adoption of user generated content initiatives by online news media
Neil outlines some of the factors that are motivations behind the media using or not using UCG.
Cost is certainly one,moderation of sites is expensive-
These costs have not yet been fully off-set by the revenues generated.
Some sites are not finding the take up particually brilliant and
Questions remain about the extent to which users are interested both in participating themselves, and viewing other readers’ contributions.
Not suprisingly though
Increasing circulation is, of course, not the only reason for eliciting reader contributions. Editors understood that secondary benefits existed as user generated content initiatives could provide a source of stories and content for stories.
Journalists and editors had some concerns about user contributions. They felt that there was a need to edit material to: avoid duplication, keep the standards of spelling and grammar high, select material that was newsworthy with broad appeal, and ensure balance and decency.and this along with legal considerations is obviously a factor in editorial policy