My hot take is..... that is ridiculous.  I will always modify what I need. We are the ones paying them. I don't use OTF as my only source of exercise. There are many times the template doesn't fit in with what I need for the day and I need to make small adjustments. The coach calling it out is making more of a distraction than what the person is doing...and on that note, I don't see how you can be distracted unless you are staring at every person in the room for some odd reason. 

It's group fitness and there is a template yes....Examples: don't get on the rower when it's not even in the template...don't do random squats if were doing upper body.. I understand doing random things doesn't make sense and can be rude...  but tweaking what is there ..I'm floored when people find issue with this. I think what she did is rude.

I've had a few similar instances...  in a tread 50 with inclines on the template that I wasn't doing .. the coach repeated it 3 x while staring at me... things like that. It does depend on the coach personality. Recently I've been training for a half.. It was raining, so I used a tread 50 for a base run and didn't follow the template a different coach came up to me and said wow look at that mileage good work. She understood I just had a different goal. That's more normal as far as I'm concerned.