Uhm, let' see if I can summarize my thoughts on this interesting topic...
I'll try to establish a few (hopefully) undisputable points:
1) KPA is an open platform. It was designed for profile sharing and the rig exchange section on their website is a great way to increase hardware selling, the core business of Kemper.
Without profile sharing the diffusion and success of KPA (but also other products, POD, Guitar rig, etc...) would have been slower, maybe too slow to grant business sustainability... but that's not the point at the moment.
2) What you buy with a commercial profile? A sound? Not entirely.
You buy the effort involved in profiling high quality profiles that "normal" users couldn't profile by themselves...
That involves the costs for having the rare amp models available (bought, rented, collected, whatever...), and/or high quality equipment for recording (mics, mixers, recording studio, etc...), and/or the time and knowledge, or skill, necessary to obtain the final product.
3) When you buy a commercial profile, you explicitly sign an agreement to use it for personal use, as a KPA owner.
Doesn't matter if you're a performer, a recording musician, or a simple amateur...
With that in mind I'd say that sharing a commercial profile is neither ethical nor legal, but in the real world:
1) Kemper doesn't necessarily have to take charge of protect the profiles.
It could, in the future, e.g. if it wanted to sell their proprietary profiles, but we are in the present now...
2a) Trying to protect the commecial profiles (taht are more than a simple "sound") is up to the sellers, that have to find a way to protect their products.
With the current open hardware platform I think it's almost impossible, but it's not a problem I have to solve. commercial profile producers have to.
2b) Another problem is: how can you reasonably detect the shared profiles? There's no tool in the KPA firmware that can compare the profile files, so do you think to go and ask to any KPA owner to binary check the memory content of their KPA (if they agree to)?
in conclusion I think that, at the moment, in theory sharing a commercial profile is a violation, but in practice without the right tools, it's impossible to avoid or persecute it, so in the end the "commercial profile" business is possible only taking sharing in account, and hoping that the loyal user base grants a sufficient income.
If this doesn't happen, it's the end of a unsustainable business that in these conditions probably wouldn't have started at all.
I personally bought some commercial profiles, and they're the best I found until now.
I'm not sharing them with anyone, but I wouldnt think to start selling my own profiles as a base to make a living...