I think what we are seeing here in the OP and in the reactions expressed in many of the follow-up posts is a combination of sometimes challenging diving at Penida along with a clash of cultures.
In terms of the challenges presented by conditions at Penida, the closest I have personally come to a dangerous situation while diving was in a down current at Blue Corner, Nusa Penida, while on a mola-mola dive. In my case the occurrence of downcurrents was not discussed by the DM, so it was a very unpleasant surprise the first time it happened. It was definitely a self-rescue situation, so I can understand the OP's alarm at what he experienced.
In terms of culture, after living and diving here in SE Asia for the past 10 years, it's my experience that Asian divers DO expect DMs to be more than simple guides and tend to elevate a divemaster to a supervisory status. I see this over and over among Singaporean and Malaysian divers here. While we don't get many Filippinos where I am, it's my guess that it's pretty much the same thing among that cultural group. Though I could be wrong, I am willing to wager that the OP is Filippino based only on his reaction to the situation and his unmet expectations regarding the supervision he feels he was provided with.
I believe this is a true cultural phenomenon related to the collectivist/individualist dichotomy that anybody who has taken sociology 101 has learned about. I'm not saying it's good diving practice for anyone to rely on the DM to the extent that Asian divers do, but I am saying that their underlying cultural organization makes it more likely that they will tend to do so. Because I am familiar with these culturally-defined attitudes, when I work with Malaysian and Singaporean divers I try to impress on them the various roles and responsibilities we all have during our dives together. (I never have worked with Japanese or Korean divers since they tend to dive only with dive pros from their own countries, but I can recognize them underwater simply by their "collectivist" behaviour, so I have reason to believe it works in a similar way with them.) As an illustration of this phenomenon, if you were to read local Malaysian or Singaporean dive board members discussing an accident, the first question is invariably, "Where was the DM?" as if the primary responsibility for prevention were assigned to the dive leader and not the divers themselves. If I am correct that this is the prevalent attitude in the Philippines as well as in my guess that the OP is Filippino, then I can really understand where he is coming from.
As an educator, I have spent my entire career working to adapt educational methodologies to local cultural expectations and needs. With that background, I believe that the Western dominance in the development of learning materials for diver education has failed to take into account the differing background cultures of student divers in that Asian students will, by default, have different expectations of anyone in a leadership role than Western students will. We can only instill in our Asian students a sense of personal responsibility as divers if we recognize the need to do so and we work to overcome cultural predispositions for over-reliance on authority figures to prevent/resolve any difficulties that may present themselves.
In terms of the challenges presented by conditions at Penida, the closest I have personally come to a dangerous situation while diving was in a down current at Blue Corner, Nusa Penida, while on a mola-mola dive. In my case the occurrence of downcurrents was not discussed by the DM, so it was a very unpleasant surprise the first time it happened. It was definitely a self-rescue situation, so I can understand the OP's alarm at what he experienced.
In terms of culture, after living and diving here in SE Asia for the past 10 years, it's my experience that Asian divers DO expect DMs to be more than simple guides and tend to elevate a divemaster to a supervisory status. I see this over and over among Singaporean and Malaysian divers here. While we don't get many Filippinos where I am, it's my guess that it's pretty much the same thing among that cultural group. Though I could be wrong, I am willing to wager that the OP is Filippino based only on his reaction to the situation and his unmet expectations regarding the supervision he feels he was provided with.
I believe this is a true cultural phenomenon related to the collectivist/individualist dichotomy that anybody who has taken sociology 101 has learned about. I'm not saying it's good diving practice for anyone to rely on the DM to the extent that Asian divers do, but I am saying that their underlying cultural organization makes it more likely that they will tend to do so. Because I am familiar with these culturally-defined attitudes, when I work with Malaysian and Singaporean divers I try to impress on them the various roles and responsibilities we all have during our dives together. (I never have worked with Japanese or Korean divers since they tend to dive only with dive pros from their own countries, but I can recognize them underwater simply by their "collectivist" behaviour, so I have reason to believe it works in a similar way with them.) As an illustration of this phenomenon, if you were to read local Malaysian or Singaporean dive board members discussing an accident, the first question is invariably, "Where was the DM?" as if the primary responsibility for prevention were assigned to the dive leader and not the divers themselves. If I am correct that this is the prevalent attitude in the Philippines as well as in my guess that the OP is Filippino, then I can really understand where he is coming from.
As an educator, I have spent my entire career working to adapt educational methodologies to local cultural expectations and needs. With that background, I believe that the Western dominance in the development of learning materials for diver education has failed to take into account the differing background cultures of student divers in that Asian students will, by default, have different expectations of anyone in a leadership role than Western students will. We can only instill in our Asian students a sense of personal responsibility as divers if we recognize the need to do so and we work to overcome cultural predispositions for over-reliance on authority figures to prevent/resolve any difficulties that may present themselves.