Where is all the new gear?

What you say isn’t completely correct. Try to use a Maschine in midi mode without passing through a computer. Not possible, because it needs drivers to be installed. A class compliant device works without any driver (which doesn’t mean that on a computer it COULD also have drivers, to make it behave in a specific way), therefore it can be used on devices like iPads or others where you can’t install them. KK keyboards? No problems. But HWs like Maschines, F1, D2 or many others need a computer to be put in midi mode. They don’t even get recognized otherwise

And we are not talking about older or newer products here: Maschine mk3 doesn’t work, Maschine+ doesn’t work, Mikro mk3 doesn’t work…but KK mk1 do work, and it’s older

I don’t think this is about fragmented development. I just think NI is still of the idea allowing their controller to be used with devices like iPads would affect their incomes. On some things NI way of thinking is very outdated. Well…on MANY things… Instead of thinking “hey…I could sell my hws also to people using other stuffs” they still think “I just want them to use MY stuff”. That’s their own right, but in my opinion THIS is how they are affecting their incomes…

NIHA and NIHIA are system services installed by NI. These services don't act as a driver but provide a middleware which is used by the NI software. These services provide a virtual MIDI device providing simplified I/O functions and translate them into a more complex HID messages and also render the pixel graphics send to the LCD displays. On macOS, there isn't any dedicated driver installed beside these services because macOS includes any required driver. On windows, an HID driver is being installed but this is just because an HID driver isn't included on windows. On Linux, there is no way to run NIHA and NIHIA because these services don't run with emulators but the device itself is recognized by standard drivers. Therefore, it is possible to make use of the device as long as you implement your own alternative to these services in your code but not to use them. Writing software for the NI hardware is a bit more work but not that difficult.

Any hardware requires a driver even if it is class-compliant. Class-compliant just means that a generic driver for a specific type of hardware is able to handle the device. But a device also needs a suitable software to make use of it. While the "MIDI part" of these USB device can be used with any DAW or virtual instrument supporting MIDI because the purpose of MIDI is clear, that is different to the HID part.

HID is a standard protocol to handle special keyboard devices. Beside the NI devices, gamer keyboards, DJ controllers and other equipment to control software are HID devices. Using the HID protocol, the computer sends messages to the keyboard to setup button backlights and other LEDs and also to configure what messages the devices shall sent when pushing a specific button or turning a specific knob. And the devices theirselves send HID messages anytime a button is pushed and so on; not very different to MIDI.

But because any HID keyboard contains an individual set of knobs and buttons, individual lights and individual label because it is designed to control a specific software, they don't fulfill a generic purpose even if the drivers and the protocols are standardized. In case of NI, this is Traktor, Komplete Kontrol and the Maschine software. Theoretically, you may use the Maschine to play computer games by using mislabelled buttons to fire and so on and also a game controller to make music but because this is senseless and would confuse any user, inappropriate devices usually aren't listed.