The answer is simple, the solution is not.
Note: This is a bit of a rant, as I completely dislike the current state of motorcycle electronic design!
<YOU HAVE Been WARNED>
Bike electrical systems are unreliable because the design requirements specify a life of probably 3 years. This is a marketing, cost and competition decision, based on what each company sees their competitors doing.
Once this is defined, all the trouble starts.
Only two things will change this:
1. At least one company will have to decide they can increase their market share by improving their reliability. This would be a big risk, not likely!
2. Buyers must respond to #1. If the market isn't willing to pay more for reliability it will never happen. As long as the majority of new bike buyers respond to shiny paint and performance far more than reliability, nothing will change. Look at BMW's recent direction!!
Electical connectors are chosen because they are the cheapest available. Little to no plating is applied to either the pin or socket of connectors Where plating us used, it is primarily for manufacturing needs, and not very helpful for long term connection reliability. This leads to oxidation, corrosion and intermittent contact.
No environmental shielding is used, except for the most primitive sort. This is the least expensive.
Connections are placed wherever most convenient for manufacture and assembly, with no regard to exposure to the elements.
Metals and platings are chosen for manufacturing purposes, with no thought to the long term reliability they could provide. This is a cost decision.
In the case of the Jbox, I believe Kawasaki did the design themselves to save money. The designers were not experienced in electrical design and had no clue how to make things reliable. No reputable electronics manufacturer would do the things done in the Jbox!
"Most" of the custom designed and manufactured items such as starters, alternators, regulators and such are designed and built by companies such as Denso, Mitsubisi and similar. These generally speaking are better designed, as those companies hold themselves to a higher standard because the automotive industry has better reliability standards. This isn't universally true, I'm speaking in overall average terms.
The wire used is not designed for repeated flexing, such as at the steering head. The wire harness configuration is designed for assembly, with little to no thought about repeated flex. As long as it doesn't cause steering issues (safety) it's good enough, and cheaper.
Switches, relays, and all manner of electrical devices are chosen based on lowest cost to meet the short life requirement. They are likely to make it through the warranty period, but anything beyond that is pretty much luck.
