Well there's also the case that a main component in having your sentence reduced is expressing genuine remorse.
I'm not sure how on earth someone could be remorseful for a mala prohibitum victimless offense while simultaneously maintaining they in good faith thought they were following the law. Any expression of those two views simultaneously would in practice be seen as not much more than "sorry I got caught -- doing something I thought was legal."
Doesn't seem contradictory to explain you thought it was okay and had no ill intent, but now realize your mistake and won't do it again. Requiring regret is problematic when you're claiming innocence (didn't do it), but when all parties agree you did it, your concern is convincing them you won't do it again.
I'm not sure how on earth someone could be remorseful for a mala prohibitum victimless offense while simultaneously maintaining they in good faith thought they were following the law. Any expression of those two views simultaneously would in practice be seen as not much more than "sorry I got caught -- doing something I thought was legal."