Jesus Christ himself didn't speak Latin, and I daresay the initial conversions throughout the Holy Land and Asia Minor were done in Aramaic, and as they spread out, it was done in Greek. Latin was a latecomer in the language of the early missions.
You think Sts. Cyril and Methodius could have reached any of their people with Latin? No - they used vernacular - which enabled the peaceful conversion of a large land. Later, do you think it a mere coincidence that huge segments of populations were very pleased to ditch Latin as their liturgical language to adopt the vernacular?
When it comes down to it, the only lands converted by the Latin west were converted through force of arms and cultural extinction of their native ways - looking at the fine example of the "conversion" of Central and South America, as well as the Phillipines.
This disdain for us lesser mortals of the laity manifests itself by clericalism - where the clergy and hierarchy believe themselves above from, separate and apart from the laity allegedly served. From the article above, there was some bragging that one Polish archbishop is more fluent in Latin than in Polish - how is that a good thing? How can he reach out to his flock and to those without a gift of language? How can he help anyone? Does it really help him do his job? How can he evangelize?
Did He and Pontius Pilate communicate privately by telepathy?
You think Sts. Cyril and Methodius could have reached any of their people with Latin
Sts. Cyril and Methodius were the Apostles to the Slavs, but they were not Slavs. That should be clear enough from their names.
The Germans seemed to have converted rather peaceably despite having to use Latin in ecclesiatic ritual.
The Indians still use Syraic (Amaraic), and not Sanskrit.