Well, as someone who owns both an AFX and a KPA, I can say that your assessment doesn't ring true.
It's not so much my assessment as that of users who chose KPA over AFX after trying both. So there's not much sense arguing with me about it. I personally don't like KPA that much, I find it too limited both in terms of effects quality and ability to make adjustments even as simple as gain, without losing authenticity.
Your claim that getting a good sound from the KPA is a simple matter of finding a profile that one likes is correct, of course. But exactly how does one find that particular profile?
Well, how does one find a preset in AFX? I'd argue that the process is easier with KPA - there are commercial profiles, many of which are very good. This could have been possible with AFX using preset-cab bundles, but there are very few of those, and then many depend on third party IRs, which you have to find and obtain separately. And then those IRs are sold in packs with dozens of files which you have to dig through to find what you need. And then there's the problem of not really being able to preview anything before purchasing, pirating aside.
I think that many of these problems could go away if AxeChange worked rather differently. IMO, it would be useful if:
1) it had both free and commercial sections where one could sell/buy patches, like some app store. Right now there's no incentive in uploading anything there, and even loyal FAS experts who share presets don't use it. Heck, even FAS themselves don't use it.
2) it had many more bundles, not just presets;
3) those bundles could include commercial IRs, for a separate charge;
4) it would be integrated into Axe-Edit, with auto auditioning;
5) users actually cared to rank presets they used;
6) it would rank presets using some smart algorithm that would take into account user ranking, downloads, installs and auditions (presets that a lot of people listen to but never I stall would go below those that are installed by most after listening);
7) seamless integration with Edit and a Store could at least partially solve the problem of AxeChange being full of prehistoric presets that don't work properly or don't even load at all. This can't be solved fully because firmware updates change the sound of many presets quite dramatically, but at least it would be something.
Now, I doubt all of this will ever happen because there's a lot of work in developing and maintaining such a system, and it involves copyright deals and such, but it kind of shows that the very approach to sound Is different in AFX, which does make things somewhat more difficult. Don't get me wrong, I like this approach, but I can easily understand the frustration some new users can go through.