Saying "MB" is not an indicator of weakness.
So this comes from the last game I played. I was playing Syndra mid, and I wasn't doing too well. The enemy jax ganked me several times and I was dodging Karma really bad. I was something like 4/6/3 when this happened.
So I see the super-fed enemy Lucian and kinda-fed Karma are pushing the inhib turret bot, so I go help. I stack a sphere from where they can't see me and then my allied Alistar engages on them. I try to stun karma because I was mad at her for beating me in lane she had less hp but I missed completely. When they proceeded to escape, I said "mb" in chat. This is ali's answer:
"Stop saying MB and play like you have a brain".
Like, wtf? Can people stop thinking that apologizing means I'm stupid or something? I missed my stun, ok, whatever, but I'm sure that ali missed his eq (or qe, never played ali, dunno what it is lol) more than once yet never said sorry.
/rant