1. Teachers are typically from good middle-class backgrounds, and will naturally assume children will just learn to read because their parents basically tutored them for hundreds or thousands of hours and they just magically taught themselves.
2. It's hard for an individual practitioner to have any idea whether their methods are wonderful or absolute garbage. Look at how long it took doctors to figure out hand-washing - now think about how hard it is for a teacher with 20 students (all of various ability levels) to know whether their methods have any real impact. The kids grow up and are reading better after a year, it must be the teacher, their method must be good.
3. Boring stuff is boring for teachers. How are they meant to be entertained in class if it's just mindless drill and kill routines?
So you've got "professionals" with no idea what actually works, some weird notion that reading is easy (because they're good at it) and a choice between boring methods that some researcher claims works, and interesting methods that some other (not so nerdy) researcher also claims works (and they use bigger words that are harder to understand when they explain their ideas).