Many Manu's keep the info to themselves out of liability concerns as well.
The same people who'd whine and cry that so and so wont tell me how to program the ABS system, as an example, would be the first ones with the lawyer on speed dial, when their reprogramming failed, trying to sue the manufacturer for giving them false information or something like that.
They also have to comply with endless laws, rules, and regulations around the world as well. Just because something has a capability, does not mean that capability should be used, or is safe to use, or even legal to use.
Sometimes things are very difficult to work on, and it's best left to someone who KNOWs what they are doing, and not just thinks they know. You brick a 1500 dollar control board and the tinkering gets very expensive very fast. Or, your playing, disables some safety feature, you get in a wreck, and sure enough, here come the lawyer, THEIR PART hurt me, it wasn't MY fault!!!
There are also such things as trade secrets, which they are under zero obligation to share with others. They paid the money to develop their software, make it work with the bike so on and so forth, so why should they just give that investment away for free?
You will find that with pretty much any company, they are not going to give you their 'know how' for free, especially with the markets as competitive as they are, they are NOT going to throw away millions of R and D so their competition can get a free ride.
Aaron