Because that's much more clutter for a speed reader to cut through. Too much information is almost as bad as too little.

There's a reason that most sites have a simple thumbs up count only: It's the easiest for readers to use. No system is perfect, and the harder you try the more unintended consequences appear.

I recommend starting simple and seeing how it works for FT. Maybe we can get more elaborate later, but a simple like (and no dislike option) is the right place to start.