Why is this a thing

Simple answer....It's a thing because people are seeking acceptance.

Simple solution, file a complaint with HR. It's a workplace, not a venue for her to evangelize her lifestyle. It seems your work is being interrupted and she's apparently not doing hers. Who knows how many others she's harrassing.

Time syou have given enough fucks to make a damned poster about it
1

how many time do their coworkers mention meat