I know workouts aren't the be all and end all but, well. I doubt the Patriots even had a draftable grade on him. I honestly don't think he'd even be effective as a tight end. His closest athletic comparison is Maxx Williams, a blocking tight end. He can't block.
I'm actually pretty happy about this. Think about how hard it was for Gordon and Brady to get on the same page, and Gordon's a special player. A stiff like Benjamin will probably do the Chiefs offense more harm than good at this point. Hell, he did Cam Newton more harm than good and they had lots of time to get on the same page.