If others are concerned about security of their luggage, they are free to stand by the belt. They have as much opportunity to do so as I do. If I arrive at the belt late and others are already standing next to the belt, good for them. I will not demand that they move out of the way for me. I will be more anxious about the security of my bags, but I will not demand that others yield their space to me.

Regarding the prisoner's dilemma and such, that is sensible in an idealistic scenario, but it does not reflect the reality of this situation. People will crowd the belt, for good reasons or bad reasons, and you can't ignore that. I can't ignore it, certainly, so I stand next to the belt. Do I contribute to the problem? Possibly. But the problem is not going away because posters in this thread think it's okay to sling insults at complete strangers. If painting a buffer around the carousel works in some airports, encourage other airports to do the same. Encourage the airports to put up relevant signs. Do something that might actually be effective instead of merely complaining.

Thank you for offering arguments instead of only insults.