The Nintendo Switch’s Bluetooth controllers work with a range of different platforms, it turns out – making for some of the most flexible console controllers currently available. The Xbox One and PlayStation DualShock 4 controllers can also connect to a range of devices using Bluetooth, but the Joy-Cons seem to be ready to use with Macs out of the box with no additional software, and you may need a few additional software tools to correctly map the Joy-Con’s key layout on PC depending on your needs.

I expected something similar.

Two possibilities as to why Nintendo did that

-To help developpers test out gameplay with Nintendo accessories on a PC build of the game
-Virtual Console is coming to PC

You're assuming Nintendo had to purposefully make the controllers work with other devices... due to the nature of input devices these days most work on anything you can connect them to.

Virtual Console won't be coming to PC any time soon, it would be a smart move but not one Nintendo will take.

Wow, I gotta say I'm kind of excited that Joy-cons can be connected to the PC as I'd love to see what people can do with them... I'm just aching for a chance to really use that HD Rumble

nope, for example the WiiU pro controller can be connected using bluetooth, but you need software that work as drivers. Otherwise its useless. Same goes if you plug a PS3 controller using USB.

The fact that you don't need to install anything is not a coincidence.  accessories need Drivers, to be recognized and usable. Windows has facilited the process of getting drivers, because now the get them automatically. But, those drivers are necessary

Sure you need drivers to use hardware, but that doesn't mean all hardware needs a driver that is specifically designed for that one piece of hardware. The fact that it works straight out of the box implies that there wasn't drivers made specifically for the Switch hardware.

That is just not how it works.

I can confirm Pro's directinput PC compatibility. Pro connects to PC automatically when paired.
But didn't know they'd work on Android as well! I know what I'm gonna Pro tonight.

The joycons also work? ^^

That's exactly how it works I'm afraid, that people are plugging it in and it's working immediately without installing specific drivers... well there you go. It's already proven.

It works on MAC and Android... do you honestly believe Nintendo went out of their way to write drivers for these platforms too? Before the thing was even released?

It supports Direct Input, thus it can be used with universal input drivers that aren't made by Nintendo.