On C + after story:
It's designed to evoke an emotional, be it sad or sentimental, response in a predictable fashion much like a soap opera would be.
I was curious as to what "piece of life" genre had to offer and clannad was the first and ended up being also the last show I gave the chance. Good elements usually transcend the genre on their own, which is what I look for in art.
It's good in what it sets out to do. It creates likeable main characters, a kind-hearted boy from a pathological family is conducive to identification or sympathy for male audiences, while the good-for-nothing girl constantly questioning her self-worth is what one would expect to be representative of the majority of the female viewers.
It has to be noted, from my previous deleted comment, that the overall story is quite unnatural in that it follows the multiple choices of alternative endings from the original clannad which was a visual novel game. It's likely in that game the main character had a chance to get to know the main heroines and diverge to either good, bad or neutral outcomes to the story.
The game-like nature is especially visible towards the finale, where one of the main heroines is supposed to be dead, when after a prolonged memory flash, situation returns to a very forced, uncanny happy ending.
