It makes you respect the environments and the "wildlife" a lot more.
It also was cool because you had to learn their means of aggro, and then learn to navigate the landscape carefully to get around them, timing was important, etc.
People will say "all the danger discouraged exploration". Not for me or others I knew. Not at all. I loved going into dangerous areas to explore. A friend of mine and I once ran around Ulegrand Range (however you spell that), dodging the mobs, and looking around. We almost made ti completely around 'til a mob came just a *little* bit too close... We ended up dying lol. And it wasn't a big deal. It's just xp you'd lose. You get it back. In any case, for me it didn't discourage exploration at all. It made it more interesting and challenging. It made reaching those remote areas all the more fun.
Now, you can say XIV 1.0 had that same thing.. high level mobs and such. Unfortunately, due to various problems with 1.0 - the narrow corridor like areas in many places (even in Thanalan and Coerthas you had them) made it difficult to get past something. And the fact that mobs wouldn't show up on screen 'til you were right on top of them made it impossible to safely work out any kind of route around them. XI's areas were actually much more permissive in that way - even some of the dungeons.
I used to *love* the run from Garlaige back to Jeuno when I'd be done xp'ing for the night. Doing the whole "mob-dodging" routine on the way back always made it fun to me. It was never a cake-walk. Well, of course not until I was high enough level where nothing would aggro me and I could drop it if it did. By then, though, I wasn't leveling in Garlaige anymore
But that's one thing XI did brilliantly... put a fear of entering a new and dangerous area into you. And I loved how missions/quests required you to go into such places, using sneak and invis, or just some extremely careful timing, combined with knowledge of the mobs in the area. Like, getting the strange coral for Windurst mission.. I believe it was 2-1 (Lost for Words) and then later trying to find Nana Mihgo's "Mahogany Door" via the Horutoto Ruins. I loved the use SE made of those zones, how they worked them into the game and such. I loved how you could go into them and just explore, come across other people, say hello, toss a few friendly buffs.. maybe even group up with them for a common cause.
That's one reason I really don't like Yoshi's idea to make all dungeons instanced. He's basically eliminated that element of the game by doing so. I don't know what he has against having instances only for Raid or maybe "quest-based" type content, but having open world dungeons, caves and such to just be additional open world areas. I just don't get that at all. It's like he's taken an all or nothing mindset to it, and went for "all". In any case, it's something I'll miss in ARR.