Kind of missed the point of the post. The loot cave is just a framing to the core point. More loot is needed or similar things to the loot cave. It doesn't have to be specifically that exact location. That area provided a fun service in the game that made the mind numbingly boring grind somewhat more bearable because there was tangible gain and a shared experience with those around you. Strikes don't offer this even though they should.

You state that a bad loot system is why people used it. Except it isn't. They used it because it was free loot, plain and simple. Your post is titled "why they should bring it back." Mine was a reply as to why they won't.

Yes, people used it because it was free loot. Which is a result of a bad loot system. It was more rewarding to do that than to actually play the intended way, because of a bad loot system.

"Free loot" is not the result of a bad loot system. People will almost always take the easiest path given to them. Even with a better loot system in place, people would still use the loot cave. It's zero effort free loot, why wouldn't they?