The reason is part of our gradual change in voice. “Says” helps build drama. It helps build scenes and narratives that readers can immerse themselves in. There’s a currency about “says.” It’s breezier. Present tense is more like watching a movie, and that’s the feel we want whenever possible.
Now, not every piece needs to read that way. If we’re writing something that’s less of a feature story and more of a fund-raising rationale, “said” might read better. “Said” is sometimes better for authoritative quotes or paraphrases, where instead of building a scene we’re constructing a case.
Sometimes in feature writing we’ll mix present and past tense. It’s a way to show that a person is telling us the story now, but referring to something that happened in the past. Here’s an example from a story I just wrote from Russia. Dasha is talking about the church service where she accepted Christ 15 years ago:
As the service ended, people greeted each other. They greeted Dasha, too, with smiles and hugs.
“And the pastor came up to me. I was still worried that he would rebuke me, but he didn’t. He said, ‘Dasha, I’m so glad that you are here. Do you want your life changed?’”
“Yes, I want that.”
The pastor invited Dasha to make a decision.
“I accepted Jesus Christ,” she says. “It was the moment that my life totally changed. I understood that there is a God — not just God, but a Father who loves me so much. And I am not alone in this world.”
Here’s a deeper discussion about this from Chip Scanlan of the Poynter Institute: