Exactly. This and what Triggercut said above captured the issue for me, competely. The improved experience (for those whose use-case is improved) is that the Latest fans are saved exactly one click. In contrast, those who preferred the previous functionality have no ready replacement.
The cost-benefit is all skewed towards a marginal gain to those who are interested in consuming all content in the forum at the cost of a signficant detriment to those who tended to be selective consumers. Perhaps the first group so vastly outnumbers the second that its justified. But I’d be surprised if that was the case.