There are still free as in freedom software hardliner folks out there. The idea that every piece of revoked source code is an affront to computing rights might be less applicable in Obsidian's case since the files are still portable, and the system may be sufficiently extensible through custom plugins (you can load anything you want through the developer plugins option) that source code itself is not necessary. Though perhaps one might want to re-assure themselves that there is nothing 'malicious' happening in the software, that's only achievable with auditing it oneself and using reproducible builds. Perhaps the freedom to fork is also not as thoroughly infringed since the files are portable and reverse engineering is not impeded.