I know that you like the OPS thing and the Sabermetric stuff, but in this case it doesn't matter how you split those stats. This team achieved zero results the last 3 years, ZERO. Organizations don't live and breath from the past, trust me. They move on, and if you no longer deliver results, you go, as simple as that. Hell, how much money did he spend? and how much money did this team lose by not making the POs the last 3 years? Seems like the balance is not favorable according with his expected KPIs given by the owners vs the outcome (last 3 years). I wouldn't be surprise if JH doesn't understand about sabermetrics. What He understands and very well is about financial metrics and concepts like NPV/IRR/ROI/cash flow etc. Seems like the owners are not comfortable how these metrics look like lately.
As i said, a GM doesn't take a portion of accountability when things go good or bad but ALL of it. This is how Organizations work. This is not a matter of good intentions or feelings but results. If the owners are letting him talk with the Cubs, it's pretty clear that they realized that the gap between good intentions and expected outcome can't be borne anymore and as a result they are making his exit easier. If he he succeed there, good for him and the Cubs, but this team needs fresh blood. This ain't personal but strictly business.