And -all- decent softwares demand good tutorials.
I agree that when it comes to in-depth VI libraries, walkthrough videos and instruction manuals are a must. But I don't think it's a developer's obligation to teach you how guitarists play in order for you to know when apply articulations and when to edit MIDI controller data. That's up to you, the musician.
An example:
I create polka accordion libraries. They're simple enough that videos are not required to learn how to use them, however, a newbie MIDI composer who buys my accordion is not going to get their tracks to sound like mine. Why? Because I've been an accordion player all my life and I know how to use MIDI volume data to get realistic dynamics. Even though musicians are using the same exact library I created my tracks with, am I obligated to put out a instructional video on accordion dynamics and MIDI CC data editing so that they can make their tracks sound more like mine?
I'll go further... I think one reason there is soooo much bad MIDI in the world is because so many people get these libs, with no proper docs, and fanny about in the dark not realising how they can get the most out of the product.
I respect your opinion, but disagree. As long as a developer shows me how to access all the articulations and features their library offers, it's entirely my responsibility to learn why and when I should apply them to get the kind of performance I'm after.
If other musicians are creating killer guitar tracks with Orange Tree guitars, and doing it without the tutorials you seek, then a lack of tutorials is not the problem. Some MIDI music creators are better than others. It's as simple as that. It's up to each musician to advance their skills in the virtual world just like they would in the real world, using every resource available and practicing what they learn.
I recently released an EP that makes generous use of Orange Tree guitars. My "tutorial" was 6 1/2 years of working extensively with virtual instruments, learning how to use articulations, using and editing MIDI controller data, listening carefully to real guitar players, watching videos, assimilating information from this forum and other sources, experimenting, failing, and (hopefully) succeeding.
Buying a virtual instrument library is like buying a watercolor paint kit from and arts & crafts store. They'll show you how to set up the easel, canvas, palette, and everything else you need to get started painting... but it's up to you to learn how to paint.