The first round of net neutrality legislation in the Netherlands (2011) was adopted to stop mobile providers from charging subscribers extra for the "service" of not blocking instant messaging and VOIP applications like Whatsapp and Skype, which were eating into their revenues streams from calls and SMS (text messages).
The current round of legislation (May 2016) forbids zero-rating. It's strict only in the sense that, like the 2011 law at the time, it's ahead of what the EU is discussing at the moment. If common sense prevails over lobbying, the EU will eventually reach the same conclusion: that zero-rating is bad for consumers and new services.
The GSMA says the tighter laws in the Netherlands will 'hinder development of innovative services and consumer choice'.
With zero-rating, it's the providers who push users towards particular services (like music streaming subscriptions); without zero-rating the consumer has an equal choice between services. So clearly innovation is better served by not having zero-rating, since that will provide a level playing field for new services.