I don't get why you need to hand pump a bunch of air just to start a small generator/air compressor when I can pull a rip cord and have 10kw of power in seconds and use that to bootstrap the remainder of this startup process.

It would seem you only need to do a bunch of pumping to startup a larger engine where the smaller starter/pony motor is not working. I wouldn't describe such an engine as 'small' though.