Ren Faires are not historical events so "stitch nazis" shouldn't really have a place there. Now if it was a reenactment, where historical accuracy is the drawing force that attracts attendants, then they have their place.
Apart from Golden Spike National Historic Site I've never seen any railroad operation actually pull through with historically accurate clothing for their crews. But that's not why I'm there. I don't expect to faithfully recreate something from the past when photographing trains, unless the event is specifically billed as being a faithful recreation, like many of Pete Lerro's charters where he arranges the actors and costuming and tends to do very well.
At the 150th Anniversary event at Promontory, so many people showed up in "period costume," but it was ridiculous how little they apparently knew about the period. (one woman arrived wearing a stunning dress - from 18th century France). But they were having fun, and the event was fun, so it shouldn't matter.
Now if I were to show up at the Victorian Iron Horse Roundup next year and somebody is wearing a chrome tanned buckskin vest with fringe and a matching top hat, then I might be upset, haha.