They decided to ifdef that despite no one being able to actually point to a relevant applicable patent?
Disappointing, but likely explains why pyexiv2 chokes on CR3 files (since pyexiv2 appears not to automatically use system exiv2 libraries, but a manually-copied version of the library at build time…)
At least for a while, even after RT includes exiv2 support, this may be a problem on some OSes, distributions.