True.The current law only applies to intentional failure to conceal, which puts the burden of proof on the prosecution.
However....
When the wind blows, and a concealed firearm suddenly becomes exposed, and a citizen calls in a "OMG!!! MAN WITH A GUN!!!" call via 911, what happens?
It COULD turn out that an LEO shows up, finds the "suspect", discusses the issue with the suspect, and uses his discretion to determine that the exposure was NOT unlawful, and sends the "suspect" on his way.
OR....
It COULD turn out that the LEO fails to use discretion, and the "suspect" is taken into custody, charged, and forced to fork out hard earned cash to an attorney, and miss work in order to prove their innocence.
So while the burden of proof is indeed on the prosecution, the prosecution loses no sleep or funds as a result of the charge, however, the same can't be said for the citizen.