Why have rocker (reverse camber) snowboards become prevalent just in the last few years?

Short answer - it's the fashion and that's what the industry is pushing right now. They want you to buy a new board to replace the one you have already got. I'm quite old now, so I learned to ride on cambered boards and I first rode a rocker when I was looking for a new board a couple of years ago. The staff in my local board store said that rocker boards are easier to learn on but if you can already ride a regular camber you are probably happier sticking with what you know. After trying a range of boards, I got where they were coming from. I can see if you were going to spend all day in the park a rocker might be the way to go and they feel good in the soft snow too. But on a firm surface or at speed, a cambered board just feels a lot more planted. And here's the gotcha. I live in the UK so I pretty much have to get on a plane to go riding and I can only take one board with me. On an average day in the Alps you expect to find hard pistes in the morning, maybe pick up some baked powder off piste somewhere, then grab some piste time over lunch before the skiers have chopped it all up, look for somewhere to play in the afternoon and then ride home on a mixture of slush and ice. Only maybe one day out of ten do you get a blue-bird powder day, set the bindings back and howl at the moon. If you've packed light, you need an all-mountain board and a rocker doesn't tick all the boxes for me. I'm sure rockers are great for little rubber guys who don't shave yet and want to spend all day taking hits, and maybe they're good for beginners too but I can't really be the judge of that. I tested a Burton Flying-V and that was a pretty good compromise, but in the end I bought a Ride DH2.7 155 and I've had no regrets.

They're easier to ride for beginners.  The Lib-Tech answer is full of crap.  The target market for these boards isn't flexing them to turn, they're skidding the tail back and forth like they always have.

Rocker (also called reverse-camber)  Camber turned upside down. All skis and snowboards, rockered or cambered, when put on edge and weighted in a turn achieve reverse-camber. Cambered skis and boards produce more pressure on the snow at the tip and tail since they have to flex further to achieve this curve. The term rocker is borrowed from watersports where rocker is common. Rocker skis and snowboards offer superior float in the soft snow and increased ease of turn initiation with less chance of "catching" an edge. As skis in general get wider, rocker helps keep the new shapes maneuverable for a wider range of skiers. Wide ski and board shapes designed primarily for powder are often rockered. It is AWESOME because: Rocker offers increased float in the powder! - You're able to maintain a more balanced riding stance which saves energy and improves your reaction time. Rocker is more maneuverable - You can slash the snow, slide sideways to scrub speed, smear and butter turns. The increased mobility works great when you are in the trees or tight chutes Rocker makes park riding a dream - The less-catchy nature of a rockered ski/board allows you to initiate your spins early and gives you greater ability to recover from off-axis landings and under-spun airs. Rocker offers tons of style points - Everyone looks at you funny in the lift line and asks why your skis or snowboard are sticking up in the air and not sitting on the ground.  Just tell them rocker will change their life. Who should/can ride rockered skis and snowboards? - Everyone can ride rockered skis and snowboards and have fun. That's the beautiful thing about rocker technology. You can be a beginner or advanced rider, young or old, and benefit from riding rocker skis or snowboards. Where does rocker technology excel on the mountain? - With the possible exception of icy, pure competition environments, there are rocker profiles meant to excel in every type of skiing and snowboarding, from freeriding to powder to park and pipe.

Reverse camber boards have become more prevalent for 2 reasons: 1. They are easier to ride: You lose the 4 catchy contact points that are hard for beginners. You are much less likely to catch an edge with your contact points bent up off the snow. 2. They are more versatile: If you like riding all different kinds of terrain, but don't have the cash to buy multiple boards, a reverse camber is usually a better option. You can get a reverse camber board and it will float nicely in deep power and also press well in the park. That being said there is still lots of great benefits of having a traditional camber board. It seems like almost all companies now are doing a "hybrid" camber, that  tries to mix a best of both worlds approach. Usually with reverse camber between the feet, traditional camber under the bindings, and reverse again on the nose and tail.