You know what, they are.

I like print format for reading purposes, even if it's on my epaper tablet. The other day when I took a train for 8 hours, I printed out several papers to read on my b&w laserjet. And it's more difficult to read diagrams these days because people make them all in colour, sometimes in ways that are very difficult to read when it's converted to b&w.

I find it a real tragedy that all these efforts to turn papers into dynamic content, which I wholeheartedly applaud, ignore the still very relevant use case of printing. Every preview mechanism for camera-ready papers should include a b&w print-preview mode.

The other advantage of PDF is that "page count" still means something. There's a reason journals limit page count, and it's not because it adds a few kbs to the download. It's because long-winded papers that don't get to the point need editing.

If all goes well we won't need this software anymore. In a best case scenario the publishers start accepting HTML, and gone are the days of having to convert PDFs to something better...!