It sounds to me like it could be a pollination problem. You grew them in blocks which is the best way, but somehow the pollen has failed to reach the silks. Sometimes the male and female bits are not well co-ordinated so by the time the silks appear the pollen has all gone. If the silks and the pollen are very wet, then there is no pollen blowing, and the silks stick together unreceptively. I wonder about the fact that the plants are so tall - the pollen is produced at the top, so maybe it all just blew away before it could reach the lower silks.
What variety did you grow, and how many plants in your block? next year, choose your variety carefully for tenderness and suitability for the region you live.
That the corn which was pollinated was hard was because you had left it too late to pick - you test it with a fingernail pushed into a grain, when a milky liquid should ooze out. You can feel if your cobs have swollen just by squeezing them gently - full and plump then they're pollinated and developing well, if the outer leaves look a bit loose and wrinkled then there are not likely to be full cobs. When the grains are too hard, your hens will love them.
I'm not sure why I'm sounding as if I know what I'm talking about, because I've rarely had a good crop and I'm not bothering with corn next year