Why all the finger numbers?

One of the most frustrating things about early piano method books is the dependence on finger numbers to locate notes. (For the non-piano-geeks, this is where, instead of a student looking at sheet music, seeing which line or space a note is on, and correlating that to a piano key, is simply seeing a number written above the note which correlates to one of the 10 fingers, 1-5 for each hand, and playing that finger.) Almost all of the students who have come to me from other teachers have had issues reading music- I think that this is why. I use Faber and Faber, which is a great deal better than some, and which tries to take students on little mini-trips out of the static hand positions, but I'm still not satisfied. Even in Faber, the letter names for the complete lines and spaces are not introduced until the second book. (Level 1) Thus, students get through the first 2-6 months only knowing the notes in C position, if that, and being completely dependent on finger numbers to locate notes. Presumably the reasoning is that the reading will come with time, (that's just supposition) but I think it's better to avoid those bad habits in the first place. Students get so, so locked into the hand positions if they are fingering-dependent, and that's a hard habit to break, irrespective of the actual reading issues. Then, of course, you have the physical/technique issues that come from rigid hand placement...... Until I find a method series I'm completely satisfied with, (hint hint, publishers!!) my m.o. is:

• Students start learning the names of the lines and spaces, all of them, via backronyms, (except for FACE, which is more just letters) midway through the Primer, or as soon as they start playing on both staves.
• I consciously supplement with "extra" theory worksheets, whether by myself or others, specifically emphasizing note naming/writing.
• We sightread. This is a lesson staple, especially for those struggling with the note reading. Sometimes the sightreading in the Theory book is enough; sometimes it isn't. I'm loving my full Finale suite right now for both the worksheets and sightreading exercises. 
• As soon as students are able, I supplement with extra pieces (some original to me, some not) which specifically move the student out of the five finger position. We do this with sightreading, too- sometimes I'll hand them a sheet with random notes all over the staff and instruct them to forget about the fingering and just play the notes. 
• Sometimes, I instruct students to just forget the fingering until they have the note names, then add it back in. This is generally only necessary with older students who can play far better than they can read.

It is so, so important for us as piano teachers to refuse to let our students get by with shoddy reading skills. If they miss this skill early, it's much harder to gain, with the relearning they'll have to do. I think that learning to "speak" (read, sing, play, etc) the language of music is much more important than finishing songs quickly, or doing new songs every week. Students have a tendency to evaluate their progress based on number of songs passed- this can be rather unfortunate, because sometimes we have to go back and learn skills that they missed as a beginner or put advancing in general competency above advancing with a specific piece. I try to show them the value in basic skills (of course we are also always working on some sort of music that they can reasonably pass in a week- going for weeks without any shift in repertoire would be hard for the young ones) and point out all the ways that actually knowing your stuff really does make it much easier down the road. To me, continuing to pass pieces a student can't read is like taking lessons in a foreign language and, instead of learning vocabulary, grammar, etc , just memorizing poems in that language. I say- why memorize a specific equation when you could memorize the formula?