There was a long period when optical drives were SCSI even in otherwise IDE computer for much the same reason, and so long as box-shifters are willing to indulge this I don't think it'll go away.

Incidently, I suspect I'll be able to soak up reasonable numbers of PATA HDDs for some time yet, as will damerell. PCI cards I've just about reached the point of "got probably my lifetime's supply" for, except that I'm going to need a PCI SATA card in the forseeable future.