I agree, but I think it's just from the general cultural notion that your body is yours and you get to decide what is done with it (which then, ironically, also doesn't apply when cultural norms are different, e.g. afaik you're not allowed to keep your relatives ashes in your home in germany, even if they willed it).

As with many social conventions, it doesn't really make sense (but from what I've seen a lot of ppl do agree with it). But it does highlight how ridiculous some of the arguments against abortion are.

My general opinion is that organ donation should be opt-out. Most people aren't organ donors not due to any real objections to the practice but purely because they don't know that they aren't.

Make it easy to opt out for any reason, but also make it easy to opt back in if you change your mind, because bodily autonomy is important in any free nation.

But also people are lazy idiots and for no-brainer medical questions like vaccines and organ donation, they should have to put in a minimum amount of work to continue a bad practice for the wider population. Make the bad practice slightly more work than the good one.

In some cases there are religious reasons, but I can see this as being a useful policy even in a purely secular world. Even with the fairly stringent organ donation consent laws we have, there have been instances where it appears that there have been instances where it appears that a person was exploited in order to harvest their organs. I'm talking stuff like conflicts of interest where transplant physicians are involved with determining the death of a donor, which could be a conflict of interest, or relaxing of standards of care of a future organ donor (i.e. letting their condition decline so their organs can be harvested sooner). There are rules about this stuff, but nonetheless, there are instances where the rules appear to have been violated.

Requiring consent of the donor (or their family) may seem silly, but removing that safeguard would inevitably lead to both abuse of the organ donation system, and also a distrust of the system by prospective donors and their families (the perception of tomfoolery would be a greater risk than the actual negligence, because cases of abuse are exceptionally rare today and I expect they'd remain quite rare even if we relaxed the consent requirement).

Philosophically, it's also important to note that the organs aren't actually harvested from corpses per se, but a heavily sedated person (who may or may not still be showing brain activity). They rule the death before they've harvested the organs, I think, but the person still being alive at the time of harvest is a big deal for organ viability. I don't actually know if they ever actually harvest organs from corpses, but I do know that doing it while the donor is still alive is the standard. The point here is that it's inherently an ethically dicey proposition, similar to how deciding to switch off someone's life support of a non-donor can be a big decision for families and/or doctors. In a way, the consent requirement can be seen as a way of sidestepping the messy philosophical questions like "what even counts as being alive". Ethically, it's by far the safest approach.