Looking at the article they came back on the same a/c two days later, so unlikely to be crew hours?
Had a look at flight only fares and TUI is twice Wizzair price, £630 vs £330 in June so you see why people who book everything separately direct jump for the Wizzair flights.
And when something goes wrong moan because there was no Wizz representatives and they had to stay in “low standard” hotel?