faster, shorter and more 'limited' orgasms are nature's way of keeping men from exhausting themselves at sex instead of hunting, defending their territory, and lining up the next opportunities for orgasm. ☺
There are some trick among us 'higher' animals to partially defeat this evolutionary adaptation, but at a price...
An experiment was once done where male mice had electrodes implanted in the area of the brain that caused sexual excitement, and a lever provided so the mice could give themselves a jolt of pure joy. The mice almost starved right next to a full food dish.