81-chopper,
Well, again, it relates to the need to balance the output of the alternator to the maximum charging amps of the battery. You can't just bolt in a bigger alternator to charge the battery faster because that would soon ruin the battery. So, when you say it's a big flaw in the system because it charges too slow, what you are really referring to is that the battery is too small for the load.
If you had a bigger battery, it would carry the load better and you could install a bigger alternator to recharge the battery faster.
Now if someone comes along in this thread and says that they have a PM alternator that puts out 20 Amps and charges the battery faster, well, it doesn't really charge the battery faster. The battery can only absorb so many amps of current over time. Applying a higher amp alternator simply means that the battery will convert the extra amps to heat and boil the water out.
So, the bike could use a bigger battery and a bigger alternator, but as it is designed, it works just fine if well maintained.