Carreras make sense to a thief.
They're common enough that there are loads about, so not going to standout on
EBay/Gumtree. Yet not bargain basement bso, so enough profit - and no one's going to look suspiciously at a £400 bike up for sale for £200
Compare it to a pinerello, bianchi or other top end bikes.. They may be worth thousands, but buyers will be harder to find and more likely to check history when dropping serious money; owners will be on the lookout for them and they'll probably be well locked up.
Couple or three mid range bikes a day and you're probably sorted for your drugs of choice....