You’re mixing up “sense of realism” with “lifelike”.
48fps adds so much detail and crisp to the picture that it looks and feels as if you’re really there looking at the real people in the real environment. It makes movies look lifelike.
But you know what ticks me off about the 48fps in, for example, The Hobbit (other than making props look like props rather than real items)? Jackson (horrible director, by the way) still added (or didn’t remove) lens flares to some of the lighting. It’s one thing to use 48fps to make it as if you’re right in the middle of the action, but then don’t go and mimic effects unique to lenses.
Abrams wants to achieve a sense of realism by making it look like you’re watching a documentary or watching the events captured by a camera. 48fps would completely nullify that effect. Accentuating lens anomalies enhances it (or in the case of Abrams: often exaggerate).
I for one hope 48fps won’t become the new standard for movies. It should be an artistic choice to use it (much like lens- and/or film choice). And if a director chooses 48fps, he should stick with that choice and not have lens flares left and right whilst doing it on 48fps.
Final rant about Jackson: if it wasn’t for the popularity of Tolkien’s work, his movies (and career) would be a giant flop. He’s one of the worst blockbuster directors I’ve ever seen. His eye for composition is terrible, his use of cheesy shots (like Kung-Fu-movie-styled close-ups and frog-perspective shots) often kill the mood of any scene and it seems like he requires his actors to act badly.