Being tall used to mean something. There is something called the square-cube law. When an object increases in size, it's volume increases at a faster rate, requiring greater structural power just to maintain strength parity with a smaller object.
This is where understanding the optimal size of a design comes into play. For humans, height used to matter as it indicated whether or not the individual had access to a reliable food source. We're conditioned to looking at larger members of society as the ones with the competitive edge in survival. However, with the advent of agriculture, this ceased meaning anything. The discriminatory tendencies still exist, but we're in a point in our civilization where being tall is actually a bad thing.
Tall was relatively meaning 5'9" as a large member of society. At 5'7" I would be classified among the largest members the Roman world for instance.
Animals have an optimal height, and for human males, that is between 5'6" and 5'9". Anything above that starts to become a hindrance.
Power becomes exceedingly difficult to produce for taller humans. Before I quit going to the gym for my master's studies, I was pushing roughly 100 kg (220 lbs) in a bench press while weighing 77 kg (170 lbs). Not exactly power lifter territory, but it's decently fit. My arm span is 54 centimeters, so to push that 100 kg, I produce 529.7 joules of energy. If we take a person at 6' in height and a similar proportion body shape (limb length, body fat, etc), that 6' person could only move 92 kg of weight. The extra 3 inches in height just cut the effective work by 8%. To equal the same mass output at 6', the individual has to produce 569 joules of energy. A hypothetical individual scaled up to 6' would also weigh 96 kg (211 lbs). A taller individual has to effectively put on nearly 24% more mass than I do just to make up for physics and biology. In effect, it takes far less effort for the shorter me to keep up with the power output or a taller individual.
