I think that it is better to start of your thinking on this topic by realizing that it is not necessarily about finding 'something to protect'. It is primarily about finding something to which you wish to become entwined. This means finding something to care about so deeply that its experiences come to impact your own, not in the myopic and selfish sense, but in the sense that you come to care about it because you become or realise that you already are interconnected with it. For example, If someone you care about is hurt, then you feel pain as well. This is where 'something to protect' comes in. Once you care enough about something, then these feelings allow you to overcome the stigmatization, social ostracisation and just general plain old effort that you need to face to become optimal at protecting whatever it is you care about.
I think that in Eliezer's post he was generally talking about how having 'something to protect' allows you to be able to be a lonely dissenter and have the courage to be able to follow through with your reasoning till its end, even if it seems 'wrong' from the point of view of others. But, I think that there is more to it than just this. In general, I think that it is the basis of most bravery and courage that we see in this world.
It may be useful to think about how you can become more connected to something that you think you might already partly care about or would want to care about. Some ideas are:
I would recommend reading this book: Man's Search for Meaning
In HPMOR Eliezer makes "Something to Protect" Harry's power that the Dark Lord doesn't have. In Posture for Mental Arts Valentine from CFAR argues that it's likely a key part of having proper mental posture.
Did any of you make a conscious attempt to develop this sense of having something to protect? If so what worked for you? What didn't work?
Is there relevant academic research on the topic that's useful to know?