Because part for me about consuming media is having the artist's intent come through and exploring the ideas they put on the paper, slow or fast buildup and character development etc. When you have it summarized you really can't catch it all.
That being said I still don't think this is a bad thing, it's just my personal problem. Any artist should appreciate their art being consumed at any level and if the hooks are good enough summarization like this might even turn the viewer into a reader.