curious moment at St. Thomas

I was sick and so we missed our regular Mass time and had to go to St. Thomas Moore Cathedral in Arlington. It was interesting. I never really like it there and find the music nigh on to unbearable but the priest is a fine man who Rocky respects and he always celebrates a sober, reverent Mass and gives intelligent homilies. At the end of Mass, right before the dismissal, Father read a letter on the HHS mandate from Bishop Loverde and Archbishop DiLorenzo in Richmond. At least a quarter of the people in the pews got up and rather noisily left before the poor priest had finished reading. I found that curious. The lay staff at the cathedral are generally rude but I've never known the parishioners to be. Were they making some kind of statement by the walk out?