I release schematics for my projects, but I -rarely- release gerbers.
My reasoning is, schematics: great for repair, understanding or change to the product.
Gerbers: great to completely copy the product without putting any effort in. You can't edit a gerber. You may as well start from scratch with any more than basic changes to an already compact PCB, too. (Most of my designs use every square inch.)
I don't know though, perhaps this view is less of open source view and more of open design. I want my products to be easy to repair, maintain and learn from, but conversely I don't want someone to start making carbon copies without putting -any- effort into at least engineering it differently or improving it in some way.
I also release schematics as PDFs. GPL-EDA has some awkwardness with symbol footprints, and a lot of my library is custom. Without the toolchain and symbols being set up properly, there is no point in having the *.sch.