I think he is referring to those that don't pay close attention to what they are doing. Folks get busy and don't realize the water level in the can has dropped to low or it runs to long and the water gets to hot. I use to use a trash can until I got some good muffs. Still use a can for small out boards that can't use muffs. Using a can is fine for those that pay close attention....however...I think that people no longer pay close attention like they use to.....we have been come a disposable society....or we blame mfgrs for our own lack of attention !