I didn't read the article as being negative, just cautiously optimistic. And the search for the "grand unifaction theory" preceeds Einstein; ever since Faraday united electricity and magnetism, and especially after Maxwell united them with light, the key word in the narrative of physics has been unity We've succeeded in uniting electromagnetism with the nuclear forces, but gravity, the stubborn old goat, just won't fit in.
No reason? Denial of deliberate or intelligent design at even this level? What do these physicists want, a Book spelling it all out?
No, just evidence.
Then there is the "fine-tuning" problem. The universe appears marvelously constructed to produce stars, planets, and life.
What some would call evidence, others would call a 'problem'. Sure it's a problem if you're trying to prove to the contrary. Very telling choice of words here.