The one thing that I very much like about the EFI system, is that it gives reliable starting in sub-freezing temperatures of a machine that I use year around, and park outside. Reliable, one kick starting down to about 26 degrees F is awesome. I never had that with carburetors.
Everything else that I prefer, like simplicity, and especially repairability and modest parts cost, favors a carburetor. Replacing an O2 sensor, a fuel pump, or a throttle body, and especially the ECU, is quite uneconomical relative to the cost of a carb. Even the fuel injector is over $100. Failure of one of these critical items while far from home, would likely leave me arranging for a transport service. Failure of any two of these components, on a machine that is probably worth no more than $2500 in running condition, likely would relegate the old girl to being parted out.
Alternately, if I have a carburetor, it's likely I can get it back into some sort of operational condition with just the materials on hand.
In my opinion, the used moto market here, by and large, doesn't care much about anything other than title, mileage, but mostly cosmetic condition. There are no government inspections required for motorcycles, and many low priced, low mileage machines in excellent condition are available. I doubt that replacing an EFI with a carb. or removing an ABS system would even be noticed by most buyers, if the bike started and ran, and there weren't obvious missing components.
On the day that my fuel pump gives out, I'll get serious about switching to a carburetor. If and when, I'd like to be able remove all the ancillary components and sell them off as spares. Doesn't make much sense to me to be bringing along a $300 throttle body, just for the ride.
What options exist for replacing the ECU based ignition system? Can the existing crankshaft position sensor serve as a pickup coil for an aftermarket electronic ignition? Somebody talked about a stator change? To AVL parts?
Does the ECU perform any other functions? Safety switches, annunciator lamps etc?
I can see the logic of certain forum members advocating in favor of the EFI. These individuals seem to be in the business of repairing motorcycles, so convincing the world to accept expensive parts and high labor content are a benefit to them.