I am not registered, but I have a organ donor card (where I approve organ donations).
Background:
Germany just recently (18th of March this year) launched an online database where you can register your preference. Until then there was only a small organ donor card that you could fill out and carry with you.
Reason I haven't registered there yet is that I first need to unlock the online function on my passport (nowadays always enabled, but I still have one from when it was optional). So I'll eventually get around to doing both.
As for my reasoning behind being a donor:
I would like to receive them in an emergency (or for someone I care about to do so).
And in case I become a donor I am not there anymore to care about what people do with my organs.
I've had my donor card for a long time now (for about the same reasons as you), this solution seems at least a little better.
I would still very much welcome an "opt-out" system, or something that would make the decision mandatory for everyone. You can always say no with no questions ask, but there are likely so many people that would have no problem donating but just never thought about the topic.
Yeah, i'd have also loved if we moved to an "opt-out" system or one where you are asked to choose at some point.
If we had more than enough organs for everyone we might be able to afford the "luxury" to not adress the issue, but we don't. And compared to the very real consequences this deficit has, it really isn't a burden to reverse the burden through opt-out or at least force people to choose. Not making a choice has just as much consequences, if not more (since it leaves it ambiguous for others that might later have to make the choice for you).
And as you said the majority probably has no problem being a donor, but the default state is a form of apathy/lazyness/ignorance. So like with many other issues a top down approach would be way more effective, compared to putting the burden on every single individual to be proactive.