But that doesn't help you if your starter dies. I will admit that this scenario happens a LOT less than a battery getting too weak to start the vehicle, but it's something that a push start can often quickly remedy.I always have a portable battery jumper. Well worth the investment and its saved me on numerous occasions. Many other options for use as well.
My experience with the new push button start cars is limited to the BMW though and even then, only with an automatic transmission. Even with a keyed ignition in an automatic, you're not going to be push starting it. Regardless, I'm suspect of the new Jeep keyless system until I have positive proof that there is a way to push / bump start it like all previous manual transmission cars that I've encountered over the years.
Now, having said that, I'm pretty sure that although it might be theoretically possible to bump start my Harley, I would be hard pressed to be able to do it alone unless I just happened to park it on a nice size hill. But that is more an indication of personal physical limitations due to various injuries on my part over the years.