It's not a myth that the stock regulator is wired to the field coil and that those diagrams don't show that happening.
Yes, there are other ways to do it, but to suggest a wiring diagram that is totally different from stock as the correct way of doing it without mentioning the differences, whether better or worse, is any easy way to confuse people that might not be as familiar with the bike and the wiring.
A newbie could look at those diagrams, wire in a matching regulator/rectifier, totally leave the field coil out, and have a completely non-charging bike. They'd have enough juice in the battery to start, drive out of town, and get stranded on a back road somewhere.
For people more comfortable with electronics, yeah, the field coil could be rewired to run straight off the battery voltage, maybe wire the stock regulator to run off the kill switch with the ignition coils, or maybe someone that doesn't like kickstarting could throw a latching relay in that engages the field coil with the starter button.
Yes, there are other ways to do it, but to suggest a wiring diagram that is totally different from stock as the correct way of doing it without mentioning the differences, whether better or worse, is any easy way to confuse people that might not be as familiar with the bike and the wiring.
A newbie could look at those diagrams, wire in a matching regulator/rectifier, totally leave the field coil out, and have a completely non-charging bike. They'd have enough juice in the battery to start, drive out of town, and get stranded on a back road somewhere.
For people more comfortable with electronics, yeah, the field coil could be rewired to run straight off the battery voltage, maybe wire the stock regulator to run off the kill switch with the ignition coils, or maybe someone that doesn't like kickstarting could throw a latching relay in that engages the field coil with the starter button.