For many students the whole language approach works extremely well. They have had a great deal of experience with sounds and letters by the time they are ready to read and catch on quickly. Most children who come from homes where reading is important have great success with this approach. For them, going back to phonics once they are in school tends to slow them down. However, up to a third of these children will need some direct instruction in phonics in order to progress as needed. They will require specific lessons here and there to learn specific skills they may not have gotten through the organic acquisition of language. Additionally, children who have specific learning disabilities may need a much more structured approach to learning phonics and may struggle for years if they don't have access to this instruction.
Children who come from homes where reading is not stressed need the most support in phonics. These are children who live in homes where there is simply not a lot of experience in language. Their parents may not spend a great deal of time talking to them or reading to them when they are very young. We see this often in places where parents' literacy is lacking. You can't read to your kids if you can't read. These children require a great deal of support to acquire phonemic awareness and phonics necessary to participate in whole language activities.
The curious thing about the teaching of reading is why we ever thought there should be an OR in our conversations. Although most kids will accelerate faster in reading through whole language methods, up to a third in all classrooms would benefit from phonics and need it to make reading make sense. In low achieving communities, about half of all children need phonics. We should be talking about phonics AND whole reading in all reading classrooms. We don't seem to question this type of thing when we teach math. Teachers understand they must teach computation skills AND applications through word problems. Yet somehow in reading, there is a belief it must be either-or.
Most of my experience as a teacher has been with students who are struggling readers. I have seen firsthand the result of the lack of appropriate reading instruction. Many of these students have horrible experiences in school which lead to dropping out and possibly getting in trouble with the law. Others fail to realize their full potential because they never truly master reading in a way that allows them to access post-secondary learning. However, when older students finally are provided with direct instruction in phonics, they can soar. I have worked with countless teens and adults who learn to read for the first time. The entire world opens up for them immediately and they suddenly want to learn everything in front of them.
The teaching of reading is not mysterious. It needs to include phonemic awareness, phonics, and lots of experience with text. It is up to every teacher and school leader to ensure that all children have access to phonics AND whole language so that ALL children can find success in reading.