Bob, and the person he's retweeting, deliberately ignores the point being made. It's not that IT'S MA'AM Abby has muscles, it's that she is built like a fucking linebacker (or Senator Armstrong) during what is ostensibly the zombie apocalypse. It takes exercise and a special diet to maintain that physique, neither of which are really practical when there are zombies knocking on your door. Furthermore, biologically speaking, men are more likely to maintain that kind of muscle mass (testosterone, it's a hell of a drug), and as Neil Druckman and Sony are desperate to point out, Abby is totes a woman and certainly not a man LARPing as one.
Then again, this is Bob we're talking about. He's not thinking through this. Hell, he probably tweeted this with one hand while the other desperately rooted through his fat, looking for his stiffie.