The biggest advantage to the Frontier was the fact that it had been around forever in its current form. The drivetrain was proven and reliable.
I can understand their need/want to add power, but they're sacrificing the known good qualities of the old engine.
Maybe this drivetrain is a pre-cursor to a complete update in the coming years.
I see it as the current engine not being made anymore because they are ramping up on the new model, whatever is left of the old model gets the new powerplant until it's time to switch over. The ancient Frontier is the only vehicle I have appreciated as much as I have, decent ride, decent f/e, zero issues, comfortable seating, first brake job at 110k.
It's a good vehicle. Some would say it hasn't kept up with its competition with regards to technology, comfort, etc. I think that would be missing the point. Unfortunately, I think the general public wants the technology/comfort, so Frontier's sales numbers have suffered.
I guess they couldn't keep going on like this forever. At some point, they would be forced to either update the truck, or cancel it outright. Given the popularity of the midsize market right now, it only makes sense to update the Frontier to a new model. The good news is that like Ford, Nissan has a global platform that they can use as a basis for the new truck.