The binary distribution of FOP 2.2 contains the shell script fop for running FOP, within the fop/ subdirectory. In previous versions the mode of this script was 755, however, in the 2.2 release the mode is set as 644.
This means that individual users, as well as package managers such as Homebrew, need to change the mode of the script as an additional step during setup.
I suspect that this was not intentional, but rather a side effect of changing the build process for the binary distribution. If this is the case, it likely can only be resolved in the next release.