As a former competitive powerlifter, I used to "max out" a lot. Too much in fact. Going for a maximum single repetition is another way to put "maxing out" into words. Is it necessary for most people? No. Not even the competitive powerlifter -- until contest time. Most trainees shouldn't even think about going for a single maximum. Why would they? Most people want to build muscle, get harder, etc. Maxing out is about the most useless way to do this. You don't get stronger. You are just demonstrating your maximum strength (maybe) on that particular day and putting yourself in a potential bad situation especially if you just happen to pick the person next to you for a spot.
Here's a pretty good example of a "max out" gone ugly:
Save the maxing out for other activities. ;)