[@inget Participant 12 years, 6 months ago]

That didn’t work, but this does:
#bbpress-forums li.bbp-forum-freshness, li.bbp-topic-freshness { display:none; }
#bbpress-forums li.bbp-forum-info, li.bbp-topic-title { width:75%; }

but this targets ALL forums, and I just want to disable it on the front page where all forums are listed.