If you look up the TextBlade, you will immediately see why its firmware needs to be more complex than your average keyboard.

Ok, I did looked it up, and still can't find anything worth updating? Different keyboard layouts?

In the end of the day it's still a keyboard. You click the keys and it sends keycodes down a wire or using Bluteooth. What's there to update?

Well, since it uses multitouch and some smarts to figure out which letter in one of the merged keys you wanted to type, I imagine it would be more useful to update that algorithm than in a keyboard where one button press = one keycode. This goes especially so if that algorithm uses any text based prediction, although I don't know whether it does. The multitouch, combined with an accelerometer I read the device has, could also be used to add interesting gestures or pressure-sensitive functionality that don't directly map to key presses. You could send the raw data over the air instead of using firmware on the device, but then nothing would be able to use it out of the box, so what's the advantage?

I think you're being purposefully obtuse here. This device is obviously more complicated than a standard keyboard and would definitely benefit from having a) sophisticated firmware, and b) the ability to update the firmware.

"keyboards have been built for decades which had no bugs."

Keyboards also haven't changed significantly for decades, we still use the same basic design, exterior(QWERTY) and interior(keyboard matrix circuit).