This. Even in Christian circles, many major works remain in Latin because publishers know they can't profitably commission the effort. This creates a situation in which for-profit publishers occasionally fund non-profit translation efforts to preserve the history.
For example, a shockingly small amount of John Calvin's works are translated into English. Regardless of what a person thinks of his theology, his influence on the rise of democracy in post-Reformation Europe and the Americas is staggering.
Most of his sermons and letters are still not in print in English, as well as a treatise on the Trinity, off the top of my head. Granted, as you point out, a large number of his works are in English but given his influence, it's surprising how many remain inaccessible.
There was a Latin collection that contained some of these works called the Corpus Reformatorum published in the 1800s.
