[Next_rim]

So your saying that if you take mid you have more control... Inst that a part of a strategic manoeuvre in most cases, and therefore should have earned and deserve the upper hand for doing so?

Not in sc2. For example, in PvZ current protoss units have very little capability to take and hold a position, unlike zerg highly mobile balls. Where terran can secure an area of the map with a siege line, protoss relies on spread out observers and slowly rolling tightly packed deathball, or fast, yet fragile blink stalker ball. Check out recent Heart vs DRG on Daybreak, where Heart would sit in mid map with a 200/200 stalker immortal ball, but still retreat at mere sight of DRG's roach pack to a more favorable choke closer to main, because there is no way even that direct counter can take on zerg's infinite production in such position.

Above being said, a map should grant a defender advantage in terms of walk distance between bases to prevent a high mobile and powerful army abusing the mere mechanics of the game (such is immortals being slow, and no other unit being capable of effectively deal with a roach ball). Attacker should never be able to move from main to 4th ramp faster than defender (save rare occasions).