Demographics and Financial Factors apply!
There are not many girls here, more now than there were in the past. Many of the single women here have paid huge sums to get a visa. Will they jeapordise this by having a boyfriend when they can be deported immediately for illicit relations!
Also there must be at least 5 single men for every one single woman in Doha, many of them are Hindu or Muslim girls or else maids who's relationships are controlled by parents or sponsors. This leaves a very small pool of girls who can pick and choose who they want as a boyfriend. If you want one go somewhere else where more universal values apply.