Lincoln is choosing to build the brand slowly, starting with the foundation (Dealer experience, dedicated design team) rather than throwing billions at a couple of flagship vehicles.
Lincoln could improve sales a lot by throwing more cash on the hoods but they don't need to do that right now and if they did it would cheapen the brand even more and make it harder when the new vehicles get here. Even the MKZ is a stop gap, albeit a good one.
I know you can't understand anything other than sales volume but at this point it's simply not relevant.