There are going to be different explanations for each athlete on why so many are injured - some may not be looking after themselves while others may be unfortunate (biomechanics related injury, illness etc).
But the landscape of the sport in the UK and globally does not help.
Eg in 2002 Steinle ran 2.09.17 for 8th at London. Good run and 90sec faster than Eamonn Martin ran to win in 93.
What does he do next? He could settle for aiming for 2.09 again. But that wouldn’t take him anywhere, especially in 21st century marathon running. He thought it would take about 2.06 to move him to what was perceived as the next level. That’s what he went for and he got injured.
Hindsight is 20:20 but what should he, or athletes in his position do? The sport is truly global with the depth of talent at the top level greater than ever. The B Grand Prix circuit (and other races that used to act as steps on the ladder) have disappeared. The sport, like others, is moving towards fewer and fewer bigger and bigger events. Instead of progressing a step at a time many athletes are now looking at leaps being needed to make the next level. Eg where do you go to run a 13.10-13.20 5K?
Gone are the days when there would be several coaches who had squads of guys running from club level to international standard with most things in between. Those squads don’t exist so much any more, look at the rankings lists. That makes it harder for both the athlete and coach to see and plan a clearly defined progression to the next level. Those who have coached squads like that in the past now have to take account of the different landscape of the sport so can’t just do it in the same way as they did in the past when planning competition etc.
I interviewed Wilson Kipketer recently and he thinks unrealistic pressures to develop too quickly are what are killing young Western athletes. They have huge expectation on them and are expected to improve steeply all the time. He blamed the media and people within the sport (agents etc) who wish to attach themselves to the next big thing and have to make a song and dance about them to get them into races, get them in the papers and get them the money. He certainly knows what he is talking about.
I think financial pressure is another factor. Despite what people think the money is not great at anything but the very top level. In athletics terms a four year development plan may be ideal but is it financially viable? Do you risk being out of the job market and housing market for that long? Big sacrifice on what might be a long shot. Easy to see why people go all or bust (or decide to give it a year) even if it’s not the best thing to do in athletics terms.
Some coaches don’t seem to have such good rates of injury but it is a tough situation to address. The issues around preparing a runner to compete in Osaka in a major championship with a tough climate are pretty complex. We don’t have many athletes or coaches used to dealing with that as the depth of talent in the UK is pretty low. So what do you do? You could take athletes away from their old coaches and move them to coaches with the experience of this but who don’t know the athlete so well (Kipketer also spoke about how relocating is not always a good idea as you lose/have to change all your support structures). Or do you leave them with the existing coach?