I also vote yes. There is no reason why an individual player can claim ownership to something so limited as End portals. It's ridiculous.
It would be one thing if you could make personal End portals... But when there are only 3 in the map, and they're all monopolized upon, there's a problem. And I wouldn't blame any players who decided to dig around a privatized door to access one.
Maybe if there were some kind of 'regen world' for the ender dimension, or if it were reset every month or two, like the nether is, it wouldn't be such an issue.
Another way this could potentially be remedied, is if Zerg put in a pubic-use End Portal in spawn? Of course, that's just a thought.