As Boycott rightly mentioned yesterday on TMS (kept me going as I decorated), the art of test batting is diminishing. It'll be a lost art soon.. the way cricket is going with kids growing up watching T20 - none of the test teams are going to be batting long periods anymore - would like us to be a bit different in that aspect.
Yes you need people who can quickly add the runs so you can runaway with a sizeable lead, but your top order also needs consistency.
How many tests now make the full five days? Many finish early now. It's not entirely the reason, but there is now a lot of emphasis on strike rates.
That's instead of the traditional lower strike rate for your opening order (tiring the bowlers) and staying at the crease for long periods.
I was always brought up (as an opening batsman) to develop the art of the leave, block and occasional run. Only if you can then go for it.
You might have only got two or three runs an over on average at the start, yet when you got comfortable you could start brining up the rate.
Now the kids as you rightly mention are taught to in the mainstay to try and slog and drive; then they're surprised when they're bowled out.