I don't believe much in penance. (The dictionary I checked said "self punishment as a sign of repentance". I don't think either aspect is valuable.) It's not related to the question of how we should treat people when they have conditions that are often under voluntary control.
We should convince them that (assuming they agree that it would be better to not have the condition) their best approach is to accept that the condition is at least partially under voluntary control, that control always appears hard, and therefore to change their lifestyle so as to address the problem. If they agree that the condition is a problem, and they find a magic bullet to solve the problem, then no penance is required. If there's no magic bullet, then they can try to change their lifestyle, but there is no need to for them to punish themselves for not understanding the situation before.




The game of Science vs. Nature is more complicated than that, and it's the interesting structure that allows scientists to make predictions that are better than "what we've seen so far is everything there is." In particular, the interesting things in both Chemistry and particle Physics is that scientists were able to find regularities in the data (the Periodic Table is one example) that led them to predict missing particles. Once they knew what properties to look for, they usually were able to find them. When a theory predicts particles that aren't revealed when the right apparatus is constructed, we drop the theory.
But in the meantime, you'd have a more interesting game (and closer to Zendo) if Nature gave you a way of classifying objects. In Zendo, there is only one dimension. Something is a match (I forget Zendo's terminology) or it isn't. [In the real world, one of the possible moves is inventing a new test. "If I hold the object up to the light, what do I see?"] Some new tests turn out not to reveal anything useful, while others give you a whole new way of categorizing all the things you thought you knew about before.
In this context, Occam's razor is a rule about inventing rules to explain complex behavior, not rules about how many things there are. Your objective is to explain a pile of evidence, and you get to make up whatever story you like, but in the end, your story has to guide you in predicting something that hasn't happened yet. If you can make better predictions than other scientists, you can have as complicated a rule as you like. If you and they make the same predictions, then the observers get to break the tie by deciding which rule is simpler.