It's true that there are a plenty of cheap PDF creation tools your users could download and use. However, you're aware of the "garbage in, garbage out" theory, and perhaps have even been burned by your users submitting a PDF with 72dpi graphics or missing fonts. When users create their own PDFs, as a print fulfillment service you'd need to check for things like:
Many end users aren't well-versed in these settings ("that's your job, not mine," they'd argue); and even ones that are may not always remember to specify all the settings correctly each time. When left to the end user, you're pretty much guaranteed to receive a hodgepodge of PDFs of different quality. Some PDFs may print correctly; some may print incorrectly (requiring another cycle of "send back to submitter for revision and resubmission"); some may not print at all.
(maybe a few graphics here: - "Some PDF Creator" -> PDF -> missing fonts -> reject - "Another PDF Creator" -> PDF -> poor overprint handling -> reject)PDF JobReady changes all of this. With a print workflow solution using PDF JobReady, print fulfillment service houses would embed their device-specific PDF creation settings into the printer driver. These settings are hidden and canoot be changed by the user. This ensures that all end users printing to this printer driver create consistent PDFs with correct settings, from any application, every time.
(graphic: - "PDFJobReady-based printer driver" -> success every time!