I think the reason it appeared in poor taste was that he appeared to be blaming Manning, and all Manning did was not lie to his manager and trainer - which would be a stupid policy for any young player. If Jack is just bemoaning the general state of the game, fine, but he didn't make that explicit.
To me the weird thing is that despite athletes in the modern era getting faster, stronger, better in almost every way, we still have this weird idea that somehow off all the athletes in the world, baseball pitchers have made the choice to go soft. I think that is not a very credible view. I'm sure pitchers today train more and harder than their average predecessors ever did. It apparently doesn't help given what is being demanded of them. In fact maybe over training is the problem. If the dominant injury is UCL *wearout* maybe guys need to be throwing far less and saving it for games only - though I think that had been tried as well without it making any difference. Whatever - it's clear the people in the sport do not understand the source of the problem, or just won't or can't do anything about it (too many breaking balls being thrown?). The only thing I'm pretty sure of is that it's not because today's pitchers are 'soft' as athletes.