Probably because the motorcycle manufacturers depend upon programmers to make things work right. I am pretty sure that I had a Yamaha around 1980 that had self-canceling indicators, along with a lamp that would let you know when a headlight or tail light had burned out. Those features were likely activated either by some sort of mechanical device or by a simple electrical circuit that didn't any coding.
Yeah, my 1984 Yamaha would let me know if the headlight burnt out and if it did, it would switch on the high beam at reduced power. It would also let me know if I was low on brake fluid and many other such things that I have not seen in modern bikes. I think you figured out the reason why.
Also, back then, gear indicators worked a lot better. Most of the new ones are calculated, which makes them useless when they are the most needed. We get a "-" whenever the clutch is in. Even on my 40K$ Harley.
But my 2013 TTSE still uses a mechanical gear indicator.
But of course, the very best way of all is to have no gears at all to indicate.
There are a lot of advantages to the older bikes. But the same goes for the newer. And ICE. And electric. Best to have a few of each.
-Don- Reno, NV