It could potentially be fixed by overmolding the USB-C connector: keep the connector, but stick it in a little jacket to make it foolproof. A bit like etherCON[0]: compatible, but way more rugged. They actually already have variants for USB-A![1]
There is already a USB-C variant, but that one seems a bit lacking.[2]
I thought we were talking about USB-C as the interface between the battery and the tool. If that's the case, the connector would be embedded in the battery so it mates with the receptacle when you clip the battery onto the tool. There wouldn't be something you can put a sleeve on (and that wouldn't be necessary as the case of the battery is, effectively, the ruggedized sleeve.)
I have an SBC that mates with an external hard drive in this way. You put the hard drive in an enclosure that clamps onto the base of the SBC and a USB-C connector mates when you do.
That's what needs to be more rugged. It's not just external side-to-side forces here, it's the actual mating and unmating of the connector that needs to be ruggedized. USB-C is too delicate for that, at least in my experience.
You want something that has big, beefy contacts that can handle being connected and disconnected a lot, by people who are not being anything close to careful when they're doing it.
If the battery already had to slide into place, it the jack & plug were already pre-aligned, I think the connector reliability would be absurdly good.
The biggest on the job problem would probably shift away from mechanical stress entirely, & be an issue of degree. Sawdust & gunk getting into the jack or plug.
I agree that a better connector would be awesome. I'd love a high amp big leafy thing.