Your main is sufficiently saturated at 16 supply that early in the game.
And where is this giant vulnerability? I'm destroying the ladder, and all my builds consist of 15 hatch, bar those which block my natural expo.
double stalker can be a cunt to deal with since speed is so late, proxy double 9/10 gates will kill you (but im assuming you drone scout early anyway so rule that out), and agressive forge openings can fuck you up as well putting you behind on maps like temple & shakurus where you can actually forge FE as protoss.
Against terran tho you're forced to 14 or 15 hat or you just die horribly to 2 rax, lololol.