I have the same question. I spent about 2 hours with an Adobe support expert who told me that Apple computers cannot export to postscript files. I actually don't believe that.
I have a mid 2012 Apple Macbook Pro with OSX Sierra and a 2016 iMac also with Sierra, and on both cases the export to postscript file doesn't work. The print booklet to postscript file exports only even pages, and these are also not entirely exported. The top part of the pages is missing.
I have the same problem. I have been using the "print booklet" option in InDesign and I use a postscript driver on a Mac--so my booklets always export to a postscript file. Until I upgraded to InDesign CC 2017 (the newest version) it always worked. Now that I have upgraded to InDesign CC 2017, printing to a booklet does not work--it cuts off the spread (and crops the page it does export). I also cannot change the orientation of the page in the print setup--for example, I need to export booklets (with crops and bleed) onto a 18"x12" page for printing; when I try to set up this size, it will only let me enter the page size as 12" wide and 18" tall--I need the page to be oriented landscape, not portrait.
The print preview will show the entire booklet spread--left and right sides and oriented landscape; but when it exports to a postscript file, it only shows the even pages and they are cut off.
I cannot export the file as a regular pdf because I need the pages to be interposed for booklet printing. Exporting it as spreads does not work either because this will not interpose the pages for booklet printing.