TLDR: Adults don't like the sound of children sounding out words slowly and would prefer not to have to listen to it.

The old way of getting around this was having kids memorize whole words.

That never really worked, so the new technique is to teach them several different strategies to guess what it is they are reading.

It turns out (no duh) that doesn't work either, but it does mask the signs of illiteracy, so that intervention ends up coming later.