All very true. And obviously the high handicapper (me, for instance) is going to make a poor contact often enough to make it sensible to lay up rather than attempt the carry over a hazard that would require me to hit my best possible shot.
But if there's no particular trouble in the way I'm going to take the club that will get the required distance if I hit it properly. My "average" distance, counted to include the bad shots, is completely unhelpful in terms of planning my way round the course, because I'll almost never hit it the "average" distance. i'll either hit it properly or screw up and be much shorter, or off-line. There's no point in taking a five iron when I'm 150 yards from the green just because I sometimes mishit it.
Don't assume that you will make bad contact with any club, or it will probably come true. Irons are harder to hit well. When tired, these are more than likely the first things to go awry. Let's say you only drive 200 yards (carry and roll). You are more likely to hit a driver to make a 150 yard carry over a 7i to make even a 100 yard carry. Woods are more forgiving than irons.
Yes, I agree that full statistics are better than just an average, and indicate what you should do more accurately. However, average does indicate skill level.
BTW, I meant to address this in the post to @flopster that I agree that the lower handicaps have every right to be suspicious of any claim a 17/18 handicap will make for any driver distances over 240 yards. For the benefit of higher handicaps making these distance claims, the reason is because even a mediocre somewhat off line tee shot you would be less than 100 yards to the pin on many normal par 4 holes. The first question would be "How could anyone take 4 shots from inside 100 yards?". Okay, point taken. Laugh away, because no matter what, it is laughable.