The novelty of finding caves wore off a long time ago. They're everywhere in the game now. You usually only have to walk a short distance from the starting point. Also, it's likely that the first cave you find is the only one you ever need to find. With the addition of ravines, if you explore every branch within the cave (including digging out dirt and gravel filled tunnels) tunnels tend to branch just slightly more often than they terminate. If you want to go cave exploring, you never need to find a brand new cave.
At first I was going to suggest just making them much less common, but a more interesting solution would be to mirror reality, and have caves confined to specific areas. Real caves form where large masses of soluble rock like limestone and marble are present. Although Minecraft doesn't differentiate different types of rock, this effect can be simulated by making a biome specifically for caves (and with the huge biomes in the current version, you can still get some pretty extensive caves).
A karst biome surface would be mostly grass-covered with a few scattered trees. The landscape would be low hills that are jagged in places, with cliffs and sharp pointy spires (as influenced by some of the biggest karst areas in east Asia). And of course there would be cave openings.
This would really help separate the concepts of mining in caves and having to just mine the rock. Finding an area with caves would be great if you want faster access to ores. On the other hand, non-karst biomes would be better suited for regular mining to get stone blocks and not have to worry as much about opening caves while mining. I guess there should probably still be patches of dirt and gravel in non-karst biomes, but no open air passages.
I agree that caves are a little too common. But that doesn't mean that the entire game should be changed simply to reflect reality. Mining through stone for hours at a time sounds a lot less fun than exploring massive cave systems while fighting off monsters every step of the way. This persistent idea that Minecraft needs to be realistic is fairly silly. You're playing a game filled with volcanic glass that makes portals to a hellish dimension, zombies, exploding green creatures, blue diamonds that you can make into swords, and a red dust that works like wires. What makes all of the people playing this game think, "Wow, this is a cool game. It should totally be more realistic."? Sorry for the rant, but I'm sick of people that suggest ideas that would ruin the game for the sake of "realism" or "ub3r l33t gunz."
At first I was going to suggest just making them much less common, but a more interesting solution would be to mirror reality, and have caves confined to specific areas. Real caves form where large masses of soluble rock like limestone and marble are present. Although Minecraft doesn't differentiate different types of rock, this effect can be simulated by making a biome specifically for caves (and with the huge biomes in the current version, you can still get some pretty extensive caves).
A karst biome surface would be mostly grass-covered with a few scattered trees. The landscape would be low hills that are jagged in places, with cliffs and sharp pointy spires (as influenced by some of the biggest karst areas in east Asia). And of course there would be cave openings.
This would really help separate the concepts of mining in caves and having to just mine the rock. Finding an area with caves would be great if you want faster access to ores. On the other hand, non-karst biomes would be better suited for regular mining to get stone blocks and not have to worry as much about opening caves while mining. I guess there should probably still be patches of dirt and gravel in non-karst biomes, but no open air passages.