TV’s Frink said:
My least favorite scene in ANH was when Vader kills Obi-Wan. That scene totally blows because it forced unnecessary emotion on us, because Obi dies with someone he’s only in one scene with.

The scene wasn’t emotional because of Vader/Obi-Wan, it was emotional because of Luke/Obi-Wan. They had a lot of history together, on-screen, and Obi-Wan was Luke’s mentor. As soon as Vader strikes Obi-Wan down, which happens very quickly, there is a quick cut to Luke’s reaction. The director understood that the most important aspect of the scene was Luke’s reaction to his mentor’s death.

In TFA, on the other hand, the director focused almost all of the attention on the interaction between Han and Kylo. The slow frame rate killed the scene. Just brutal. There were cutaway shots to Leia, Chew, and Rey, but they all failed for various reasons.