I've seen this discussion run back & forth more than once on the ImageFX mailing list.
People with long held ties to the professional printing industry see it as essential. Many (most?) who came to Amiga graphics from any other direction tend to hold DPI as less important, or even a hinderence.
Personally I think DPI is about as important as an 8.3 file name restriction. Just one more parameter some programs with a perfectly good GUI want you to wrestle with. I'll take an image and print it how I want to, not at the size a DPI setting dictates.
Perish forbid, but I'm even going to mention the Evil Empire. AFAIK, no M$ Office application requires DPI data. And yes, I've seen lots of people at work stretch images until single pixels are the size of small postage stamps.
DPI may be important to desktop publishing programs that prepare files for printing service bureaus. To me anything else is unnecessary.
Sure a sample is a sample, but a player program that has to be told the sample rate before playing is just poor coding. Does your JPEG viewer demand to know what rate of compression you used to save the file?
