It's a combination of a difficult pitch and really poor technique from modern batsmen. I get that there are issues with the pitch, and the up and down bounce can't really be tolerated as it can become dangerous (though I've seen worse on the sub-continent), but professional batsmen should be able to counter the sideways movement a lot better. Cover your stumps, play inside the line and don't follow the ball, and defend with soft hands so if you edge it, it doesn't fly into the slips. Do that until the shine is off the ball, then look to up the ante. This is just test cricket 101, but what I see these days is batsmen playing with hard hands early so every edge flies in the air, failing to cover their stumps (how are they getting beaten on the outside and still get bowled?!), and an inability to concentrate for long enough period of time to survive if the ball moves around for a while. T20 has a lot to answer for...
A 300+ score against a pitch with sideways movement should be well within reach.