When a publisher has made the majority of the expected revenue off a property they're pretty unlikely to want to donate some more dev time out of the goodness of their heart. I think historical trends have also shown that DRM is almost always left in place - so I think the empirical data is pointing strongly at a lack of any organic motivation to de-DRM any products.
Most of the time an anti-DRM patch gets rolled out it's either a company/individual that has strong personal feelings about DRM (i.e. somebody like Stardock) or else it's a patch that the devs wrote way back when to make testing in some environment easier that they kept around and valid out of the goodness of their hearts. I think in almost all cases it boils down to someone who personally disagrees with the prevailing business opinion that DRM is good and actually has enough political power in the company to force their opinion onto the business at large.
Most of the time an anti-DRM patch gets rolled out it's either a company/individual that has strong personal feelings about DRM (i.e. somebody like Stardock) or else it's a patch that the devs wrote way back when to make testing in some environment easier that they kept around and valid out of the goodness of their hearts. I think in almost all cases it boils down to someone who personally disagrees with the prevailing business opinion that DRM is good and actually has enough political power in the company to force their opinion onto the business at large.