Well, perhaps I could provide another viewpoint...
Wedding photography has been a "sore point" for many of the photo studios here for a long time (there were instances of photographers from different studios actually fighting over who gets to shoot a wedding sometimes...

)
With the advent of digisnappers, the situation got worse - there are many "moonlighters" taking away their bread and butter, so someone must have tipped the inspectors. They came, saw that the guy shooting the weeding (for money) did not have a business license (i.e. was not operating legally, not paying any taxes, dues, etc.), so naturally they fined him.
Like in any other civilized country, you cannot sell your products/services in Croatia unless you're some kind of a registered business, which means that you're providing your customers with regular bills/invoices, paying your taxes, insurances, etc... I bet all of the hotdog sellers in NY must also have some kind of license, unless they want to be busted, right?
The point is that it's just another "illegal activity", just like various street peddlers pushing contraband and/or counterfeit goods, and the inspectors have the full right to check whether the person providing the service (for money) is licensed to do so...
A different problem is that they have obviously taken the issue too far, so that they (allegedly) said that noone is allowed to take ANY photos at the wedding, unless they have the proper business license.
Yes, some things are done in rather strange ways here - take the issue of busnesses/stores being open on Sundays. The unions were complaining about being forced by the employers to work in the stores on Sundays, without being paid extra. So, after several months/years of endless debates, the Parliament, in its infinite wisdom, decided not to allow ANY stores to be open on Sundays - apparently it was a lot easier to do than having to control whether the workers in those stores are actually properly paid for their work
So, if you want to buy some bread in the nearby store on Sunday - tough luck!
Denis from Croatia