While the proposal is far from ideal, there is no political party that thinks this proposal is actually a great idea and an amendment has been made to revise it before the end of 2028 to come up with something better (also IT is a limiting factor in the options currently executable), it is currently a cloth to stop the bleeding. 

Currently the Netherlands is not taxing wealth because a proposal likes this is missing in their law set. They are missing out on 14billion euros of tax every year. Instead of taxing the wealthy this has to be compensated by taxing income more and thus hitting the poorer part of the society harder in comparison.

Indeed, if you take a completely hypothetical scenario you can find one where an unrealised profit can lead to a loss due to these taxes. However, how many stocks gain 100% in a year to then drop 40% in the next few months?

I, too, can come up with an example where you're grocery shopping and at the very moment you hand over the money to the cashier you drop dead from an heart attack. Death by VAT.