I'd be wary of calling it a tax. As you pointed out it's an amount large enough to warr off spurious medical needs and small enough that if you're really injured or suffering, it can be extremely helpful and is a miniscule part of your medical fees.

What's broken is the huisarts system where any efforts to get specialized care when you're in pain must pass through your GP. This often leads to a longer waiting period that can be excruciatingly painful for some.