I feel it's a bit like the usability vs security dilemma.. you can try to optimize to have both, but then you won't have as a result neither the most secure system nor the smoothest user-friendly experience, but something in between (you might still consider that "secure" or "usable", but that just depends on where you set your expectations).
If you want to maximize marketing then the result won't be as ethical as it could be, and if you want to maximize ethics then the result won't be as marketable as it could be.