This heavily depends on the SLA, the use case or the industry. Working on ultra low latency systems for algorithmic trading I can tell you we actually care and

This heavily depends on the SLA, the use case or the industry. Working on ultra low latency systems for algorithmic trading I can tell you we actually care and hunt down maxes more than the 95th percentile. They tend to be much bigher outliers in HFT and the transactions you typically loose money on.