My husband is a normal, intelligent person but he never reads. In the 45 years that I have known him, he has read one book, a non-fiction account of the Shiwa Ngandu estate in Zambia. He was interested because he saw Michael Palin visit it. He says that Treasure Island is his favourite book. As far as I can make out, it was the only book he ever read when he was at school in Uganda.
I taught both of our girls to read before they went to school, and neither had any difficulties. Elder DD is a voracious reader. Younger DD read a lot when they didn't have a TV, but has now succumbed to the lure of films. She only reads occasionally. I don't know why they are different. Both have been fluent readers since they were tiny, both are imaginative, so why does one read lots and the other reads little?
I don't think you can push it. A reluctant reader as a child may very well change and become keen. (Adults are less likely to change. I have bought my DH books I thought would interest him. They are untouched. I adore books - never thought I would marry a non-reader!)
My dad, who taught reading to so-called "backward" children, said that it didn't matter what kids read. Let them read comics. The important thing is for them to enjoy reading.
Yep, slow learners were called "backward" in the 60s. Dad was the local treasurer of the Guild of Teachers of Backward Children. It wasn't considered offensive.