Sure. But without seeing the other sides argument, I have to wonder if their point wasn't that they're not designed to be stable for the purpose of identifying a service/thing on the Internet; things can and do move and change. Hardware failure is a good example of that. Just like a house address, those too are normally stable but people can & do move. Just with software, it's like we look our friend up in the white pages¹ prior to every visit, which one might not do in real life.
¹oh God I'm dating myself here.