I have never heard of that incompatibility before. I have had nothing but Intel motherboard for ages and obviously before SATA all the DVD drives were using PATA and only recently has there been more of an emphasis on SATA.
In my case, my motherboard only has six SATA connectors. Four for my RAID, one for a 5th HD, and one for a SATA DVD but frankly, I think I bought it thinking I was getting a PATA drive. I had to disable my external eSATA port so I could free up the 6th SATA connector for the DVD drive.
Add-on SATA controllers are pretty expensive. I have seen 4-port SATA controllers that cost as much as motherboards.
I am going to bet there are others like me who are short of SATA connectors and want to use what we have. As it is, I wish my motherboard offered a second PATA controller to attach two more drives.
Can you refer me to some articles or discussion regarding the incompatibility of PATA and optical? I can't imagine how we managed to do it all those years prior to SATA and can't now?