You purchase the switch with a provided charger. If that charger caused issues, then there's potentially a suit. It's not obvious that you'd say the same thing if they used a proprietary port like what the 3DS uses.
No, I purchase a device with a Universal charger port and a universal charger. If the device doesn't work with any other universal charger that is their problem. Likewise if I use their charger on something else and it breaks my other device that is their problem.
The purpose of universal is everything works with everything. whoever breaks that is at fault and should pay the price. If Nintendo has used some other port I wouldn't have the expectation, but they used a universal port so they need to be compatible.
Nintendo clearly states on Switch specs page that the Switch dock has a "AC adapter port". Just because it uses a connector that physically looks like USB Type-C does not mean it's actually a USB type C port.
It should be considered the same, because for all practical purposes, that's how the end users treat it - and it's not unreasonable on their behalf. If Nintendo wants a proprietary charger, they're welcome to use a proprietary port. But standards exist for a reason, and diluting them like that should be heavily regulated.
While they don't explicitly claim USB-C compatibility, creating a USB-C shaped port seems like a pretty clear representation that the dock is USB-C compatible.
