The guy has negative charisma, basically checked out of his Senate job, is known mostly for supporting citizen path legislation that the base hates, and never had any chance of winning this primary. This article is just "if only he'd been good he'd win as pundits said he would!".
I don't like the the theater criticism version of politics, but the entire candidacy of Marco Rubio was premised on the idea that he was a dreamboat. And, you know, he wasn't. He's repulsive.