I had no idea there were any traditions associated with messenger bags...
Thing is, NO other manufacturer stipulates or mandates cross-body wear for their products - I know, because once ONA made that nonsensical claim I checked other manufacturers websites assiduously.
I think we may be onto something here.
I am quite confident that Ona (and possibly other manufacturers as well) do not explicitly state how to wear a messenger bag because they believe this is inherent to the concept:
A messenger bag (also called a courier bag) is a type of sack, usually made out of some kind of cloth (natural or synthetic), that is worn over one shoulder with a strap that goes across the chest resting the bag on the lower back.
Messenger bag - Wikipedia, the free encyclopedia
Messenger bag - Wikipedia, the free encyclopedia
or:
A large bag with a long strap, worn across the body.
messenger bag - definition of messenger bag in English | Oxford Dictionaries
messenger bag - definition of messenger bag in English | Oxford Dictionaries
Kinda like they don't explicitly tell you to wear shoes on your feet, lest you should want to put them on your hands.
I very rarely wear a bag cross-body. It hangs from my right shoulder (I am sinistral) and I access it with my right hand. Above all, a cross-body bag looks frankly ridiculous when worn with a suit and ruins the cut.
In that case, you are definitely looking for a regular shoulder bag, not a messenger bag.
The ONA Brixton definitely had fixed partitions, something I found bizarrely and frustrating in daily use.
Then they must have redesigned the insert at some point. I only ever saw it as shown on their product page, which is with "traditional" dividers.
ONA | The Brixton - Smoke - Camera and laptop messenger bags
Ultimately, bags are a very personal thing. I freely admit I have far too many, since I struggle to get rid of them. Which I suppose says something about the Brixton which got eBayed long before ONA's indefensible defence of their product.
Amen to the subjective nature of camera bags. I have gone through quite a number of them for various reasons (one size does not fit all, evolving gear collection, different shooting style, environmental considerations, etc.) despite the extensive amount of information available.
But while their manners may have been lacking, I do not quite agree that Ona's response is indefensible.