At DebConf I whined at Mark Shuttleworth about my fears that Ubuntu is reducing Debian to a supermarket of components (an analogy that was introduced entirely innocently by someone else during an unrelated talk). At least, that seems to be the kind of comment that I later heard some Ubuntu people characterize as whining. Anyway, NewsForge ran an article about DebConf that included a mention of that, and I had to follow up with a comment explaining a bit more about the problem. I'll reproduce it here:

The problem with everyone treating Debian as a supermarket is that it ends up with Debian == sunsiteWmetalab. Giant un-integrated collections of software are not particularly interesting in a lot of ways.

My main motive for contributing to Debian is to make Debian the best distro I can; I don't mind if others use that work, especially if stuff gets contributed back. But it's long been clear to me that the most important added value to Debian is not adding another package to the shelf, but finding new ways to integrate our software together. When you're working mostly above the level of individual software packages, to have your work mostly appreciated on the basis of "component contained in Ubuntu" is not very motivating.

If that motive goes away I fear Debian could be left with mostly developers who are happily motivated with just packaging another peice of software. While there's nothing wrong with feeling that way and working on that basis, we don't want to lose the people who want to work on things that cut across sets of packages, like speeding up the boot time, improving the installation experience, making the distribution attractive for speakers of $language, making sure Debian supports as much hardware as best it can, porting Debian to interesting new architectures, integrating Xen and SE Linux with Debian, making a useful default desktop install, etc.

Some of these are exactly the areas in which Ubuntu is apparently better than Debian, and in most of those cases, contributing individual patches back to Debian is simply not enough for Debian to share Ubuntu's improvements. It puts Debian at best in the position of wasting a lot of time trying to play catch-up and figure out how a collection of patches to different packages fits together into a coherent overall improvement.