Ya know, I wouldn't want to lose the Police Box altogether, but, it would be cool, if sometimes, it did actually work properly and do something to blend in at crucial times.
Like maybe a couple times a Series the Chameleon circuit actually worked properly when landing somewhere he definitely didn't want to be recognized, or maybe someplace where seeing the Phone Box would be detrimental to a Society's development
The Sixth Doctor actually managed to temporarily repair the Chameleon Circuit in "Attack of the Cybermen", and we saw the TARDIS as both an ornate piece of furniture
and an organ
As for the Chameleon Circuit not currently working, I give you Eleven's own words on that:
Itís camouflaged. Itís disguised as a police telephone box from 1963. Every time the TARDIS materialises in a new location, within the first nanosecond of landing, it analyses its surroundings, calculates a twelve-dimensional data map of everything within a thousand-mile radius and then determines which outer shell would best blend in with the environment.... and then it disguises itself as a police telephone box from 1963.