TFA is kind of lacking details and I don't follow Hungarian politics that closely, but my first instinct has to do with Viktor Orban's government - he's known for some controversial laws curbing media freedom and changes to their constitution which got the entire EU worried.
The main confusion is that consent can be given in many different ways: implicit consent is still a consent and the article mentions one of their government ministers saying you are fine as long as nobody is explicitly asking you not to take a picture.
Unfortunately, Hungarian is so hard to understand that even with Google Translate I can't follow their newspapers and columns, so we are at the mercy of second-hand journalism and skimpy stuff such as TFA, but indeed this looks like one of the laws enected to be used selectively against well defined targets.
Meanwhile, don't cancel your Hungarian vacation just yet - it's a lovely country with things to see and do, even without taking a camera
P.S. Personally, I welcome this law. When traveling through Hungary, I can stop paying Hungarian vignette (road tax) and when I drive under highway cameras, I'll just wave my arms in explicit objection to having my picture taken