Fuel injected motorcycles don’t have reserve (at least, none that I’ve seen.) instead they have low fuel lights or full fuel gauges. I’m guessing it’s because the fuel pumps are in the tank and the fuel injection system needs high pressure.

Fuel injectors require filtered gas because even small particles can clog them, and said filter is more likely to be clogged or even compromised by sucking up the last drops of fuel (and scale and debris) in the tank, so the low-fuel warning is required.

Carb jets can get clogged, too, but are wider since they're not under as much pressure. Also, since they're a wear item they're a lot easier to clean and/or replace.

I think grandparent commenter had it right: it's because the pump is in the tank. There's just no good way to have an external petcock determine where a tank-internal pump gets its fuel from.

Many new bikes come with a lot of rider aids for safety (ABS, TCS) as well as all kinds of electronics (fuel maps), so this is changing. But of course manual transmission won't go away until bike are electric.

I am one of those who likes things old school. My bike still has a carburetor, has no fuel light or tachometer, and I have certainly had some practice reaching down to turn the fuel petcock to reserve while sputtering on the highway. If they didn't intend for me to do that, why did they put it on the left side? :)

> But of course manual transmission won't go away until bike are electric.

See multiple Honda bikes with DCT (dual clutch transmission). This is what I'm planning to get as my first bike.

Goldwings also have a reverse gear. Even more remarkable: I used to have an Aprilia scooter that had a remote release button (on the key fob) for the under-seat storage area. I think I used it once just to see if it works.