…venues don’t actually ever say that DSLRs are prohibited. They don’t know that word, so they use a term they’ve made up: detachable lens camera. This is a bullshit term that has no meaning outside this context.
ANY camera can have the lens detached if you pull hard enough!
Besides this being a stupid way of differentiating “allowed” and “not allowed” camera gear (one can “attach” a lens to an iphone if they so choose), I highly doubt that the average door/gate person can tell the difference between this “detachable lens camera” and this “non-detachable lens camera“. Heck, the average PHOTOGRAPHER can’t tell the difference.
This criteria could also become a liability if bouncers start trying to rip lenses off cameras.