Again, that's a big assumption. Plausible problems:
1. developing language skills early stunts development of more visual skills
2. too much structured time has drawbacks
3. "it ought to be at worst a waste of time" ... and additional stress. Opportunity costs could also include relationship capital (pushing your kid to do unimportant things means you can't push as hard in other areas).
The author of the article went into detail as to what possible harm there could be, and why he thought they were avoided or null.
Your stance seems to be summarized as: 'what if parents are thoughtless, naive, and too forceful?'.
In this case, the author was none of that, and really shouldn't be compared to this hypothetical worst case scenario.
> developing language skills early stunts development of more visual skills
This seems incredibly unlikely. I'd in fact bet money that developing any skill young will not stunt the growth of another skill, so long as a normal amount of time is spent invested in that other skill comparative to normal children.
> too much structured time has drawbacks
Indeed, but according to the author all they did was read to the child before dinner, and have them sound out words as they pointed to them. Does 30 minutes to an hour of reading and pointing count as too much structured time?
> Opportunity costs could also include relationship capital (pushing your kid to do unimportant things means you can't push as hard in other areas).
This sounds like a problem of methodology, not of aims. If teaching a child anything causes alienation, then you are doing it wrong, especially if that thing is a basic skill that they must learn.
Again, that's a big assumption. Plausible problems:
1. developing language skills early stunts development of more visual skills
2. too much structured time has drawbacks
3. "it ought to be at worst a waste of time" ... and additional stress. Opportunity costs could also include relationship capital (pushing your kid to do unimportant things means you can't push as hard in other areas).