Question: I'm doing a total kitchen renovation with solid hardwood flooring. Do I go hardwood all the way under the cabinets to the wall or stop just past the toe kick and finish the rest with ply of the same thickness?

Answer: 
In your situation, using real 3/4" hardwood flooring should be a lifetime floor. I cannot see any reason to remove it as any other type of flooring in the future could be installed right over it. Since it is much more likely to have some type of cabinet upgrade rather than actually needing to remove the hardwood, I would install the hardwood wall to wall and install cabinets over it. The actual extra amount of hardwood used under the cabinet area is minimal, and will make installation easier and faster than working around the cabinet footprint.
I ran mine all the way to the wall. Turned out to be a good thing because I made a cabinet change which pushed everything down six inches.