Just as you used to do on ODT, whenever you result to this type of rhetoric, you've already conceded the point. I suppose the implication is that anyone who would assume there is a weapon in an instrument case is either unintelligent, a hillbilly, or a thug....it's really difficult to tell given the godawful attempt at inflection and phonetic expression in the sentence. Having said that, I'm sure you're proud of it...so there is that.
It has nothing to do with the size of the case and everything to do with the context of it. Regardless of what you perceive to be someone's intelligence or their relationship status with their father's brother, if they're not on their way to the country club for a tennis match, why would they have a tennis bag slung over their shoulder? Further, there is zero reason to believe that someone would have any reason to carry a violin around with them in public unless said person was wearing a tuxedo or had one in a hanging bag draped across their shoulders. Contextually, a violin case in a grocery store doesn't add up...you don't need a violin in a grocery store, so what else is in it? Same with the tennis bag carry idea.
I realize that you are personally invested in this system and probably think very highly of it and yourself, but try not to take it personally that it's a terrible system. Trust me, you're not nearly as "grey" as you think you are.