I would suggest that you read the 2CA decision. It seems self explanatory to me. "The Supreme Court's “fee jurisprudence” has historically addressed the constitutionality of fees charged by governmental entities on expressive activities protected by the First Amendment—such as fees charged to hold a rally or parade." It was determined that the fees did not exceed the costs so it was acceptable. It is the same public safety issue you see in other cases. It is not limited to the 2A. SCOTUS passed on the issue because it is not inconsistent with what it has said in the past on similar issues.
An INDIVIDUAL'S exercise of a fundamental right, is FAR removed from a group of individuals wanting to rally or parade on the public streets.