Design documents for a product that is obsolete and one that they no longer support. Get real.
Trust me when I say that there is nothing at all unusual in the Vetta design. In fact the reason I bought the Vetta I have in the first place is because it is just about exactly what I thought a guitar amp design should look like in this day and time.
It's not really the hardware design, it's the code for it that is the real proprietary bit but there are tools around to disassemble that kinda stuff too if you're sufficiently motivated.
If a competitor really wants it, they can get it easy enough without Line6 putting their customers though so much BS and using that as a lame excuse.
BTW may of the parts like the DSPs have been superceded by better models now but you can still get them from a lot of sources the specialize in obsolete parts. The rest are common garden variety parts obtainable from many traditional electronic component source.
In the end, there is no good reason not to provide their users with the support they should and not doing so is doing more to harm their market share than not. From what I've seen so far, customer service and after sale support in the musical instrument business is really crappy by comparison to other markets I know that none of you would stand for it for one second with the cars, computers or anything else that you all buy. Their attitude is just plane crappy and the only reason they can get away with it at all is because all the dummies out there who put up with it. Pretty much the same reason why Washington is in the mess it's in today too.