That's the Prague - Zurich NightJet that's hellishly expensive, possibly because the target audience are Swiss people for whom it's not so much :D Also, NightJet does not price very dynamically as opposed to other providers, and their baseline price is always quite high.

But yes, in most cases this journey will be more expensive that an alternative flight, which is a shame. However, there are routes where it's comparable, e.g. the Prague - Amsterdam route.