No one is “calling for” a Bumgarner/Chavis trade. No one. So far all we have is some people who say it’s a good idea or a fair trade. As far as anyone knows, neither side has even acknowledged there is anything to this rumor beyond it being just that, a rumor.
But I will reiterate my viewpoint, which is that if DD pursues an angle like this, it is a fair trade for both sides. If I were GM, I’d only pull the trigger after knowing the full scope of the deal and (assuming the full scope was acceptable) had some sort of insurance about Bumgarner’s health, since he’s only pitched 240 IP in the last two seasons combined.
Chavis might be excellent. He might be mediocre. And three years from now, he might fall into the abyss of Garin Cecchini/Steve Lomasney types that no one remembers. The odds are heavily stacked against him being excellent - so few are - but he has beaten them to date. Once the league gets a second look at him and how he adjusts will be a big factor in seeing what he really is...