True, we can't really get by without *all* of the current app's in real world situations, especially in the case of mag ad's & editorial.
That said, I have found that where printers were very reluctant to embrace change a few years ago, many of them are willing to be re-educated these days in terms of new software. Perhaps it comes down to the fact that until relatively recently Quark had no serious competition, so printers were at liberty to dictate the file formats that they would except.
With ID's increased popularity they probably can't afford to be so *traditional* in their approach... We have adopted a policy of dropping printers who won't work with our chosen tools. This, of course, doesn't really work with newspapers and the like.