I think it might do more harm than good, even in its intended targets. In Forum Adventures, even a simple "seconded!" post gives the thread an often much-needed bump and helps it from getting buried. In a fast-moving art thread, quoting a picture or story to say "This is really great!" can be a great way to make sure more people see it. Personally, I think the current
lack of an upvoting system benefits authors and artists more than the ability to Like posts would. And if you're just worried about your thread being unreadable due to all the contentless posts, then you should really be posting your adventure directly to a mirror or manually stringing the updates together with
[ POST ] tags.