By that logic you also don’t feel bad for people who die in car accidents because from the first time they got behind a wheel they knew of the possibility. You should also not feel bad about people who are ran over, from the first time you walked outside your parents told you it was a possibility. Every time you go outside you’re risking being hit by a car, so don’t expect me to cry when that happens, right?.. Right?..
No, life is full of dangers, and ODing is just one of them. Most people who OD are in a bad situation and started using drugs to cope, and then it took control of them. Almost none of them made a conscious decision to OD, and one could argue their road to using that amount of drugs was also not entirely their choice, after all lots of those cause chemical dependency. Think about this, someone is stressed at work, they’re offered a cigarette by a friend who smokes daily, they smoke it and feel the stress going away, are able to focus and get through that tough spot, so they do it again next time they’re stressed, and then they start to get more and more stressed, but now they’re hooked, and trying to quit will be extremely difficult… Would you really not feel bad if that person developed cancer because he was stressed once and a friend offered a cigarette? How is ODing any different?