I oppose the idea of a "Like" button.
Over the years, FT's mature and thoughtful discussions have frequently helped me make sense of awful and tragic events. (For current examples of this, see the threads about MH370 and QZ8501.) I don't see how a "like" button would improve the quality of that type of thread.
I have also been here when the community reacted to truly awful events involving community members-- such as the untimely demise of a young FT member (who was a frequent poster in the Delta forum). Do we really want to have "like" buttons under posts about the passing of a member?
What about the times when active FT members suddenly are exposed as public figures -- what possible good could come out of having "like" buttons under posts about a FT member's highly-publicized dispute over a trivial matter?
Hate-filled comments also appear on FT -- whenever a TSA employee is arrested for something, there are bound to be several hate-filled posts about the employee, their alleged crime and/or their employer. The annual devaluations of FF programs also cause angry hate-filled posts. Do we really need "like" buttons under those?
What about threads that are complaints about IB and/or the site sponsors? Imagine someone posts an awful thread about a site sponsor, e.g. a "[Site Sponsor] eats children" thread -- does IB really want "like" buttons under those threads?