Starfleet engineers are known to be highly cautious.
GILORA: What are the chances that both a primary system and its backup would fail at the same time?
O'BRIEN: It's very unlikely, but in a crunch I wouldn't like to be caught without a second backup.
While this might be seen as wise by humans, the Ferengi view this as a truly deplorable trait, one that stands in the way of the pursuit of opportunity. Per their Rule of Acquisition #62;
The riskier the road, the greater the profit.
The Ferengi Rules of Acquisition
There's also a strong suggestion that their scientist is an incompetent who simply doesn't recognise the danger.
ARRIDOR: They panic quickly under pressure.
TNG: The Price - Original Screenplay
Purely as an aside, it would seem that the Ferengi's instincts were (unintentionally) correct. By remaining in the vicinity of the wormhole they were able to find a brand new, uncontacted world which they were then able to take over in Voy: False Profits.