[CTcard]

I tend to think that playcalling criticisms are largely meaningless, for reasons the author indicates, but it's sort of frustrating to tell people that you have to be an expert in something to actually meaningfully criticize it ...

The one exception in my mind is run/pass ratio. 

Overall I agree with the sentiments in the two posts above. 

To add some nuance, I don't think the issue is exactly that you must be an expert - at least to criticize at the level of a message board. 

The emphasis on individual play calls is a difficulty. Many of the issues there are noted above: what happened may or may not match what was called, some calls are going to be better and worse for everybody, why an individual play fails takes a check of the film, etc. 
The default almost always seems to be: that thing they called didn't work while clearly that other thing they didn't call would have worked. The play calling focus also tends to lead people to pine for wildly different things play to play and game to game - which of course is not how an offense is constructed or learned. 

But, I see no reason not to think about offensive strategy broadly. A fan who watches can get a feeling for strengths and weaknesses of personnel, can consider the importance of establishing a base approach, the plusses and minuses of tempo, personnel matching, etc. You still have to pay attention and learn a little bit to have good insight, but it's not too hard to develop reasonable thoughts at that level. This sort of conversation can be both interesting and can help one learn a lot as well.

[CTcard]

I tend to think that playcalling criticisms are largely meaningless, for reasons the author indicates, but it's sort of frustrating to tell people that you have to be an expert in something to actually meaningfully criticize it ...

The one exception in my mind is run/pass ratio. 

Overall I agree with the sentiments in the two posts above. 

To add some nuance, I don't think the issue is exactly that you must be an expert - at least to criticize at the level of a message board. 

The emphasis on individual play calls is a difficulty. Many of the issues there are noted above: what happened may or may not match what was called, some calls are going to be better and worse for everybody, why an individual play fails takes a check of the film, etc. 
The default almost always seems to be: that thing they called didn't work while clearly that other thing they didn't call would have worked. The play calling focus also tends to lead people to pine for wildly different things play to play and game to game - which of course is not how an offense is constructed or learned. 

But, I see no reason not to think about offensive strategy broadly. A fan who watches can get a feeling for strengths and weaknesses of personnel, can consider the importance of establishing a base approach, the plusses and minuses of tempo, personnel matching, etc. You still have to pay attention and learn a little bit to have good insight, but it's not too hard to develop reasonable thoughts at that level. This sort of conversation can be both interesting and can help one learn a lot as well.