I once worked for a place where the business unit got us to deploy one of those crappy client side A/B testing scripts which blocks rendering. Conversion rates started to dip and the same people came back to us complaining about it. I was able to pull together plenty of evidence to show them what the issue was. All they cared about was if we could A/B test it using the aforementioned client side script. Some people just can't be reasoned with, so glad I got out of that place.