This has become a bit of a sidetrack to the actual topic, so maybe stop there. The rules of FTL aren't likely something that's going to affect new player attraction or not.
However, it does bring up one of the big differences between fantasy and science fiction - sword and gun genres if you like. Fantasy has as its bedrock historical settings, usually medieval or renaissance - occasionally classical. Authors don't have to reinvent the sword or the horse, or a castle or a peasant village. Or a sailing ship. Magic and monsters tend to be fairly well defined. Nonhumans tend to be pretty human. Genre conventions are pretty settled, especially in games.
Every science fictional setting has different technological assumptions. Very few share FTL types, except in the broadest terms. Are there robots? are there energy shields? Ray guns? Bionics? Psi powers? Nonhumans are commonly very alien. Hard SF or Space Opera? Genre conventions vary wildly.
So... given that the overwhelming majority of gamers are first exposed to Fantasy RPGs, new players generally have to not just make the switch to SF RPGs, but adjust from what they expect science fiction to be, to what Traveller is, in the first place.