I've heard that Churches were locked on Christmas. That it was basically wrong to celebrate.

Do you think this was due to the pagan/roman influence on Christmas traditions? Anyone understand this?

Christmas has been celebrated in December since the late 300s.

At least according to Calvinist traditions, specifically English Puritans and Presbyterians, the idea was that they used the Bible as a guide to recreate the 1st century church as closely as they could. So if it wasn't mentioned in the Bible, it was seen as a later imposition made by humans, often due to incorporating pagan beliefs and rituals. Christmas certainly fit that description, and Christmas activities in the early modern era were much more adult and less family oriented. Samuel Seward, a Puritan leader in Boston who kept a regular diary wrote about two brightly colored men accosting each other and engaging in a duel by sword on Christmas during the period of the Dominion of New England under James II when Puritan authority in Massachusetts was diminished.